Creation of virtual machine placeholders in a data storage system

ABSTRACT

The data storage system according to certain aspects can manage the archiving of virtual machines to (and restoring of virtual machines from) secondary storage. The system may archive virtual machines (VMs) that are determined to have a low level of utilization. The system may create a virtual machine placeholder for an archived VM, which may be a “light” or minimal version of the VM that acts like the actual VM. By using a VM placeholder, a VM may appear to be active and selectable by the user. When the user selects the VM, the VM placeholder can interact with the user in similar manner as the VM. Accessing the VM placeholder may trigger restore of the archived VM from secondary storage. The restore of the archived VM may be “seamless” to the user since the VM remains available while it is being restored.

RELATED APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet, or any correction thereto,are hereby incorporated by reference into this application under 37 CFR1.57.

BACKGROUND

Businesses worldwide recognize the commercial value of their data andseek reliable, cost-effective ways to protect the information stored ontheir computer networks while minimizing impact on productivity.Protecting information is often part of a routine process that isperformed within an organization.

A company might back up critical computing systems such as databases,file servers, web servers, and so on as part of a daily, weekly, ormonthly maintenance schedule. The company may similarly protectcomputing systems used by each of its employees, such as those used byan accounting department, marketing department, engineering department,and so forth.

Given the rapidly expanding volume of data under management, companiesalso continue to seek innovative techniques for managing data growth, inaddition to protecting data. For instance, companies often implementmigration techniques for moving data to lower cost storage over time anddata reduction techniques for reducing redundant data, pruning lowerpriority data, etc.

Enterprises also increasingly view their stored data as a valuableasset. Along these lines, customers are looking for solutions that notonly protect and manage, but also leverage their data. For instance,solutions providing data analysis capabilities, improved datapresentation and access features, and the like, are in increasingdemand.

Enterprises may use virtual machines in order to utilize physicalresources in a more efficient manner. Virtual machines that have lowutilization may be archived in order to reduce the amount of unused orunderused resources. In some cases, archived virtual machines may needto be restored.

SUMMARY

Due to the above challenges, there is a need for managing virtualmachines, and in particular, virtual machines that do not fully utilizethe resources allocated to them. Although many users request largeamounts of resources for the virtual machines, in most cases, they donot use the allocated resources frequently, and generally not to thefull extent of the allocated resources. In order to address these andother challenges, certain storage systems disclosed herein areconfigured to archive virtual machines that have low usage. A datastorage system according to certain aspects may include a virtualmachine (VM) archiving module that manages the archiving of virtualmachines to, and restoring of virtual machines from, secondary storage.One or more virtual machines may run on one or more client computers inthe system. Each client computer may include a hypervisor that controlsand manages the one or more virtual machines on the client.

The VM archiving module can determine whether to archive virtualmachines based on usage data or information. The system may monitor theusage of virtual machines, for example, according to a schedule, basedon certain events, at a system administrator's request, etc. Themonitoring of virtual machines may be implemented as storage policies.The VM archiving module can obtain the usage data or information fromthe hypervisor on each client. The VM archiving module may also obtainthe usage information from a virtual center that collects informationrelating to various virtual machines in the system. The usageinformation may include storage usage, CPU usage, memory usage, networkusage, events defined by a virtual machine software or application, etc.

The VM archiving module may archive the virtual machines that aredetermined to have a low level of utilization. Such determination may bemade when the usage level of a virtual machine is below a thresholdlevel of activity. The VM archiving module can initiate copying of thevirtual machine and its associated data from primary storage (e.g., theclient computer and/or an information store associated with the clientcomputer) to secondary storage. In some embodiments, the VM archivingmodule may reduce the amount of resources allocated to a virtual machine(e.g., in increments) until a threshold level of activity is reached.The virtual machine can be archived when the usage level reaches thethreshold level. In order to reduce the amount of allocated resources,the VM archiving module may move the low usage virtual machine tolow-cost and/or low-speed storage. Once the virtual machine and theassociated data are copied to secondary storage, the virtual machine andthe associated data in primary storage can be pruned.

The virtual machine archiving module may create a virtual machineplaceholder for an archived virtual machine. A VM placeholder may be a“light” or minimal version of the virtual machine that acts as if it isthe actual virtual machine. The VM placeholder may have a reduced set oramount of resources compared to the VM. The VM placeholder can interactwith one or more operating systems on the one or more client computerslike it is the virtual machine. In this way, a virtual machine may bearchived, but still appear to be active and selectable by the user.

When a user accesses the virtual machine or the VM placeholder after thevirtual machine has been archived, at least a portion of the virtualmachine and its associated data may be restored to reactivate thevirtual machine. Resources may be allocated to the restored virtualmachine. The VM placeholder may be deleted after all of the virtualmachine and its data are restored to primary storage.

In this manner, the data storage system according to certain aspects canreduce the amount of resources that are unutilized and/or underutilizedby virtual machines. The virtual machines with low usage may also bemigrated or moved from high cost storage to low cost storage (e.g., fromsolid state drive to hard drive). In this way, the system can decreasethe costs associated with storage and other resources. The system mayalso provide seamless archiving and restoring of the virtual machinesthrough the use of virtual machine placeholders. From a user'sperspective, the virtual machine may appear to be available at alltimes, and the archiving and the restoring of a low usage virtualmachine can occur in the background.

According to certain embodiments, a method of archiving virtual machinesin a networked data storage system is provided. The method can includedetermining whether to archive a virtual machine (VM) executing on oneor more client computers in primary storage with computer hardwarecomprising one or more computer processors based on usage data. Themethod may further include, in response to determining that the VMshould be archived, copying the VM and its associated data from theprimary storage to secondary storage. The method can additionallyinclude creating a VM placeholder for the VM in the primary storagewherein the VM placeholder appears to be the VM. The method can furtherinclude deleting the VM and the associated data from the primarystorage. The method may also include restoring at least a portion of theVM and the associated data to the primary storage when the VMplaceholder is accessed after the VM and the associated data aredeleted.

In some embodiments, a data storage system configured for archivingvirtual machines is provided. The data storage system may include astorage manager module executing on computer hardware comprising one ormore computer processors. The storage manager module can be configuredto initiate copying of data from primary storage to secondary storage.The data storage system may also include a virtual machine archivingmodule executing on computer hardware comprising one or more computerprocessors. The virtual machine archiving module can be configured todetermine whether to archive a virtual machine (VM) executing on one ormore client computers in the primary storage based on usage data. Thevirtual machine archiving module may be further configured to, inresponse to determining that the VM should be archived, initiate copyingof the VM and its associated data, by the storage manager, from theprimary storage to the secondary storage. The virtual machine archivingmodule can be further configured to create a VM placeholder for the VMin the primary storage wherein the VM placeholder appears to be the VM.The virtual machine archiving module may also be configured to deletethe VM and the associated data from the primary storage. The virtualmachine archiving module can also be configured to restore at least aportion of the VM and the associated data to the primary storage whenthe VM placeholder is accessed after the VM and the associated data aredeleted.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIG. 2 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary storage system configured toarchive virtual machines according to certain embodiments.

FIG. 3 is a data flow diagram illustrative of the interaction betweenthe various components of another exemplary storage system configured torestore archived virtual machines according to certain embodiments.

FIG. 4 is a flow diagram illustrative of one embodiment of a routine forarchiving virtual machines according to certain embodiments.

FIG. 5 is a flow diagram illustrative of one embodiment of a routine forrestoring archived virtual machines according to certain embodiments.

DETAILED DESCRIPTION

Systems and methods are described herein for archiving virtual machines.Examples of such systems and methods are discussed in further detailherein, e.g., with respect to FIGS. 2-5. Moreover, it will beappreciated virtual machines may be archived, migrated, and/or restoredby information management systems such as those that will now bedescribed with respect to FIGS. 1A-1E. And, as will be described, thecomponentry for implementing virtual machine archiving functionality canbe incorporated into such systems.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot afford to take the risk of losing criticaldata. Moreover, runaway data growth and other modern realities makeprotecting and managing data an increasingly difficult task. There istherefore a need for efficient, powerful, and user-friendly solutionsfor protecting and managing data.

Depending on the size of the organization, there are typically many dataproduction sources which are under the purview of tens, hundreds, oreven thousands of employees or other individuals. In the past,individual employees were sometimes responsible for managing andprotecting their data. A patchwork of hardware and software pointsolutions have been applied in other cases. These solutions were oftenprovided by different vendors and had limited or no interoperability.

Certain embodiments described herein provide systems and methods capableof addressing these and other shortcomings of prior approaches byimplementing unified, organization-wide information management. FIG. 1Ashows one such information management system 100, which generallyincludes combinations of hardware and software configured to protect andmanage data and metadata generated and used by the various computingdevices in the information management system 100.

The organization which employs the information management system 100 maybe a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents and patent application publications assigned toCommVault Systems, Inc., each of which is hereby incorporated in itsentirety by reference herein:

-   -   U.S. Pat. Pub. No. 2010-0332456, entitled “DATA OBJECT STORE AND        SERVER FOR A CLOUD STORAGE ENVIRONMENT, INCLUDING DATA        DEDUPLICATION AND DATA MANAGEMENT ACROSS MULTIPLE CLOUD STORAGE        SITES”;    -   U.S. Pat. No. 7,035,880, entitled “MODULAR BACKUP AND RETRIEVAL        SYSTEM USED IN CONJUNCTION WITH A STORAGE AREA NETWORK”;    -   U.S. Pat. No. 7,343,453, entitled “HIERARCHICAL SYSTEMS AND        METHODS FOR PROVIDING A UNIFIED VIEW OF STORAGE INFORMATION”;    -   U.S. Pat. No. 7,395,282, entitled “HIERARCHICAL BACKUP AND        RETRIEVAL SYSTEM”;    -   U.S. Pat. No. 7,246,207, entitled “SYSTEM AND METHOD FOR        DYNAMICALLY PERFORMING STORAGE OPERATIONS IN A COMPUTER        NETWORK”;    -   U.S. Pat. No. 7,747,579, entitled “METABASE FOR FACILITATING        DATA CLASSIFICATION”;    -   U.S. Pat. No. 8,229,954, entitled “MANAGING COPIES OF DATA”;    -   U.S. Pat. No. 7,617,262, entitled “SYSTEM AND METHODS FOR        MONITORING APPLICATION DATA IN A DATA REPLICATION SYSTEM”;    -   U.S. Pat. No. 7,529,782, entitled “SYSTEM AND METHODS FOR        PERFORMING A SNAPSHOT AND FOR RESTORING DATA”;    -   U.S. Pat. No. 8,230,195, entitled “SYSTEM AND METHOD FOR        PERFORMING AUXILIARY STORAGE OPERATIONS”;    -   U.S. Pat. Pub. No. 2012/0084268, entitled “CONTENT-ALIGNED,        BLOCK-BASED DEDUPLICATION”;    -   U.S. Pat. Pub. No. 2006/0224846, entitled “SYSTEM AND METHOD TO        SUPPORT SINGLE INSTANCE STORAGE OPERATIONS”;    -   U.S. Pat. Pub. No. 2009/0329534, entitled “APPLICATION-AWARE AND        REMOTE SINGLE INSTANCE DATA MANAGEMENT”;    -   U.S. Pat. Pub. No. 2012/0150826, entitled “DISTRIBUTED        DEDUPLICATED STORAGE SYSTEM”;    -   U.S. Pat. Pub. No. 2012/0150818, entitled “CLIENT-SIDE        REPOSITORY IN A NETWORKED DEDUPLICATED STORAGE SYSTEM”;    -   U.S. Pat. No. 8,170,995, entitled “METHOD AND SYSTEM FOR OFFLINE        INDEXING OF CONTENT AND CLASSIFYING STORED DATA”; and    -   U.S. Pat. No. 8,156,086, entitled “SYSTEMS AND METHODS FOR        STORED DATA VERIFICATION”.

The illustrated information management system 100 includes one or moreclient computing device 102 having at least one application 110executing thereon, and one or more primary storage devices 104 storingprimary data 112. The client computing device(s) 102 and the primarystorage devices 104 may generally be referred to in some cases as aprimary storage subsystem 117.

Depending on the context, the term “information management system” canrefer to generally all of the illustrated hardware and softwarecomponents. Or, in other instances, the term may refer to only a subsetof the illustrated components.

For instance, in some cases information management system 100 generallyrefers to a combination of specialized components used to protect, move,manage, manipulate and/or process data and metadata generated by theclient computing devices 102. However, the term may generally not referto the underlying components that generate and/or store the primary data112, such as the client computing devices 102 themselves, theapplications 110 and operating system residing on the client computingdevices 102, and the primary storage devices 104.

As an example, “information management system” may sometimes refer onlyto one or more of the following components and corresponding datastructures: storage managers, data agents, and media agents. Thesecomponents will be described in further detail below.

Client Computing Devices

There are typically a variety of sources in an organization that producedata to be protected and managed. As just one illustrative example, in acorporate environment such data sources can be employee workstations andcompany servers such as a mail server, a web server, or the like. In theinformation management system 100, the data generation sources includethe one or more client computing devices 102.

The client computing devices 102 may include, without limitation, one ormore: workstations, personal computers, desktop computers, or othertypes of generally fixed computing systems such as mainframe computersand minicomputers.

The client computing devices 102 can also include mobile or portablecomputing devices, such as one or more laptops, tablet computers,personal data assistants, mobile phones (such as smartphones), and othermobile or portable computing devices such as embedded computers, set topboxes, vehicle-mounted devices, wearable computers, etc.

In some cases, each client computing device 102 is associated with oneor more users and/or corresponding user accounts, of employees or otherindividuals.

The term “client computing device” is used herein because theinformation management system 100 generally “serves” the data managementand protection needs for the data generated by the client computingdevices 102. However, the use of this term does not imply that theclient computing devices 102 cannot be “servers” in other respects. Forinstance, a particular client computing device 102 may act as a serverwith respect to other devices, such as other client computing devices102. As just a few examples, the client computing devices 102 caninclude mail servers, file servers, database servers, and web servers.

The client computing devices 102 may additionally include virtualizedand/or cloud computing resources. For instance, one or more virtualmachines may be provided to the organization by a third-party cloudservice vendor. Or, in some embodiments, the client computing devices102 include one or more virtual machine(s) running on a virtual machinehost computing device operated by the organization. As one example, theorganization may use one virtual machine as a database server andanother virtual machine as a mail server. A virtual machine manager(VMM) (e.g., a Hypervisor) may manage the virtual machines, and resideand execute on the virtual machine host computing device.

Each client computing device 102 may have one or more applications 110(e.g., software applications) executing thereon which generate andmanipulate the data that is to be protected from loss.

The applications 110 generally facilitate the operations of anorganization (or multiple affiliated organizations), and can include,without limitation, mail server applications (e.g., Microsoft ExchangeServer), file server applications, mail client applications (e.g.,Microsoft Exchange Client), database applications (e.g., SQL, Oracle,SAP, Lotus Notes Database), word processing applications (e.g.,Microsoft Word), spreadsheet applications, financial applications,presentation applications, browser applications, mobile applications,entertainment applications, and so on.

The applications 110 can include at least one operating system (e.g.,Microsoft Windows, Mac OS X, iOS, IBM z/OS, Linux, other Unix-basedoperating systems, etc.), which may support one or more file systems andhost the other applications 110.

As shown, the client computing devices 102 and other components in theinformation management system 100 can be connected to one another viaone or more communication pathways 114. The communication pathways 114can include one or more networks or other connection types including asany of following, without limitation: the Internet, a wide area network(WAN), a local area network (LAN), a Storage Area Network (SAN), a FibreChannel connection, a Small Computer System Interface (SCSI) connection,a virtual private network (VPN), a token ring or TCP/IP based network,an intranet network, a point-to-point link, a cellular network, awireless data transmission system, a two-way cable system, aninteractive kiosk network, a satellite network, a broadband network, abaseband network, other appropriate wired, wireless, or partiallywired/wireless computer or telecommunications networks, combinations ofthe same or the like. The communication pathways 114 in some cases mayalso include application programming interfaces (APIs) including, e.g.,cloud service provider APIs, virtual machine management APIs, and hostedservice provider APIs.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 according to some embodiments is production data orother “live” data generated by the operating system and otherapplications 110 residing on a client computing device 102. The primarydata 112 is stored on the primary storage device(s) 104 and is organizedvia a file system supported by the client computing device 102. Forinstance, the client computing device(s) 102 and correspondingapplications 110 may create, access, modify, write, delete, andotherwise use primary data 112.

Primary data 112 is generally in the native format of the sourceapplication 110. According to certain aspects, primary data 112 is aninitial or first (e.g., created before any other copies or before atleast one other copy) stored copy of data generated by the sourceapplication 110. Primary data 112 in some cases is created substantiallydirectly from data generated by the corresponding source applications110.

The primary data 112 may sometimes be referred to as a “primary copy” inthe sense that it is a discrete set of data. However, the use of thisterm does not necessarily imply that the “primary copy” is a copy in thesense that it was copied or otherwise derived from another storedversion.

The primary storage devices 104 storing the primary data 112 may berelatively fast and/or expensive (e.g., a disk drive, a hard-disk array,solid state memory, etc.). In addition, primary data 112 may be intendedfor relatively short term retention (e.g., several hours, days, orweeks).

According to some embodiments, the client computing device 102 canaccess primary data 112 from the primary storage device 104 by makingconventional file system calls via the operating system. Primary data112 representing files may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. Some specific examples are described below with respect to FIG.1B.

It can be useful in performing certain tasks to break the primary data112 up into units of different granularities. In general, primary data112 can include files, directories, file system volumes, data blocks,extents, or any other types or granularities of data objects. As usedherein, a “data object” can refer to both (1) any file that is currentlyaddressable by a file system or that was previously addressable by thefile system (e.g., an archive file) and (2) a subset of such a file.

As will be described in further detail, it can also be useful inperforming certain functions of the information management system 100 toaccess and modify metadata within the primary data 112. Metadatagenerally includes information about data objects or characteristicsassociated with the data objects.

Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),to/from information for email (e.g., an email sender, recipient, etc.),creation date, file type (e.g., format or application type), lastaccessed time, application type (e.g., type of application thatgenerated the data object), location/network (e.g., a current, past orfuture location of the data object and network pathways to/from the dataobject), frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), and aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists[ACLs]), system metadata (e.g., registry information), combinations ofthe same or the like.

In addition to metadata generated by or related to file systems andoperating systems, some of the applications 110 maintain indices ofmetadata for data objects, e.g., metadata associated with individualemail messages. Thus, each data object may be associated withcorresponding metadata. The use of metadata to perform classificationand other functions is described in greater detail below.

Each of the client computing devices 102 are associated with and/or incommunication with one or more of the primary storage devices 104storing corresponding primary data 112. A client computing device 102may be considered to be “associated with” or “in communication with” aprimary storage device 104 if it is capable of one or more of: storingdata to the primary storage device 104, retrieving data from the primarystorage device 104, and modifying data retrieved from a primary storagedevice 104.

The primary storage devices 104 can include, without limitation, diskdrives, hard-disk arrays, semiconductor memory (e.g., solid statedrives), and network attached storage (NAS) devices. In some cases, theprimary storage devices 104 form part of a distributed file system. Theprimary storage devices 104 may have relatively fast I/O times and/orare relatively expensive in comparison to the secondary storage devices108. For example, the information management system 100 may generallyregularly access data and metadata stored on primary storage devices104, whereas data and metadata stored on the secondary storage devices108 is accessed relatively less frequently.

In some cases, each primary storage device 104 is dedicated to anassociated client computing devices 102. For instance, a primary storagedevice 104 in one embodiment is a local disk drive of a correspondingclient computing device 102. In other cases, one or more primary storagedevices 104 can be shared by multiple client computing devices 102. Asone example, a primary storage device 104 can be a disk array shared bya group of client computing devices 102, such as one of the followingtypes of disk arrays: EMC Clariion, EMC Symmetrix, EMC Celerra, DellEqualLogic, IBM XIV, NetApp FAS, HP EVA, and HP 3PAR.

The information management system 100 may also include hosted services(not shown), which may be hosted in some cases by an entity other thanthe organization that employs the other components of the informationmanagement system 100. For instance, the hosted services may be providedby various online service providers to the organization. Such serviceproviders can provide services including social networking services,hosted email services, or hosted productivity applications or otherhosted applications).

Hosted services may include software-as-a-service (SaaS),platform-as-a-service (PaaS), application service providers (ASPs),cloud services, or other mechanisms for delivering functionality via anetwork. As it provides services to users, each hosted service maygenerate additional data and metadata under management of theinformation management system 100, e.g., as primary data 112. In somecases, the hosted services may be accessed using one of the applications110. As an example, a hosted mail service may be accessed via browserrunning on a client computing device 102.

Secondary Copies and Exemplary Secondary Storage Devices

The primary data 112 stored on the primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112 during their normalcourse of work. Or the primary storage devices 104 can be damaged orotherwise corrupted.

For recovery and/or regulatory compliance purposes, it is thereforeuseful to generate copies of the primary data 112. Accordingly, theinformation management system 100 includes one or more secondary storagecomputing devices 106 and one or more secondary storage devices 108configured to create and store one or more secondary copies 116 of theprimary data 112 and associated metadata. The secondary storagecomputing devices 106 and the secondary storage devices 108 may bereferred to in some cases as a secondary storage subsystem 118.

Creation of secondary copies 116 can help meet information managementgoals, such as: restoring data and/or metadata if an original version(e.g., of primary data 112) is lost (e.g., by deletion, corruption, ordisaster); allowing point-in-time recovery; complying with regulatorydata retention and electronic discovery (e-discovery) requirements;reducing utilized storage capacity; facilitating organization and searchof data; improving user access to data files across multiple computingdevices and/or hosted services; and implementing data retentionpolicies.

Types of secondary copy operations can include, without limitation,backup operations, archive operations, snapshot operations, replicationoperations (e.g., continuous data replication [CDR]), data retentionpolicies such as or information lifecycle management and hierarchicalstorage management operations, and the like. These specific typesoperations are discussed in greater detail below.

Regardless of the type of secondary copy operation, the client computingdevices 102 access or receive primary data 112 and communicate the data,e.g., over the communication pathways 114, for storage in the secondarystorage device(s) 108.

A secondary copy 116 can comprise a separate stored copy of applicationdata that is derived from one or more earlier created, stored copies(e.g., derived from primary data 112 or another secondary copy 116).Secondary copies 116 can include point-in-time data, and may be intendedfor relatively long-term retention (e.g., weeks, months or years),before some or all of the data is moved to other storage or isdiscarded.

In some cases, a secondary copy 116 is a copy of application datacreated and stored subsequent to at least one other stored instance(e.g., subsequent to corresponding primary data 112 or to anothersecondary copy 116), in a different storage device than at least oneprevious stored copy, and/or remotely from at least one previous storedcopy. Secondary copies 116 may be stored in relatively slow and/or lowcost storage (e.g., magnetic tape). A secondary copy 116 may be storedin a backup or archive format, or in some other format different thanthe native source application format or other primary data format.

In some cases, secondary copies 116 are indexed so users can browse andrestore at another point in time. After creation of a secondary copy 116representative of certain primary data 112, a pointer or other locationindicia (e.g., a stub) may be placed in primary data 112, or beotherwise associated with primary data 112 to indicate the currentlocation on the secondary storage device(s) 108.

Since an instance a data object or metadata in primary data 112 maychange over time as it is modified by an application 110 (or hostedservice or the operating system), the information management system 100may create and manage multiple secondary copies 116 of a particular dataobject or metadata, each representing the state of the data object inprimary data 112 at a particular point in time. Moreover, since aninstance of a data object in primary data 112 may eventually be deletedfrom the primary storage device 104 and the file system, the informationmanagement system 100 may continue to manage point-in-timerepresentations of that data object, even though the instance in primarydata 112 no longer exists.

For virtualized computing devices the operating system and otherapplications 110 of the client computing device(s) 102 may executewithin or under the management of virtualization software (e.g., a VMM),and the primary storage device(s) 104 may comprise a virtual diskcreated on a physical storage device. The information management system100 may create secondary copies 116 of the files or other data objectsin a virtual disk file and/or secondary copies 116 of the entire virtualdisk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 may be distinguished from corresponding primarydata 112 in a variety of ways, some of which will now be described.First, as discussed, secondary copies 116 can be stored in a differentformat (e.g., backup, archive, or other non-native format) than primarydata 112. For this or other reasons, secondary copies 116 may not bedirectly useable by the applications 110 of the client computing device102, e.g., via standard system calls or otherwise without modification,processing, or other intervention by the information management system100.

Secondary copies 116 are also often stored on a secondary storage device108 that is inaccessible to the applications 110 running on the clientcomputing devices 102 (and/or hosted services). Some secondary copies116 may be “offline copies,” in that they are not readily available(e.g. not mounted to tape or disk). Offline copies can include copies ofdata that the information management system 100 can access without humanintervention (e.g. tapes within an automated tape library, but not yetmounted in a drive), and copies that the information management system100 can access only with at least some human intervention (e.g. tapeslocated at an offsite storage site).

The secondary storage devices 108 can include any suitable type ofstorage device such as, without limitation, one or more tape libraries,disk drives or other magnetic, non-tape storage devices, optical mediastorage devices, solid state storage devices, NAS devices, combinationsof the same, and the like. In some cases, the secondary storage devices108 are provided in a cloud (e.g. a private cloud or one operated by athird-party vendor).

The secondary storage device(s) 108 in some cases comprises a disk arrayor a portion thereof. In some cases, a single storage device (e.g., adisk array) is used for storing both primary data 112 and at least somesecondary copies 116. In one example, a disk array capable of performinghardware snapshots stores primary data 112 and creates and storeshardware snapshots of the primary data 112 as secondary copies 116.

The Use of Intermediary Devices for Creating Secondary Copies

Creating secondary copies can be a challenging task. For instance, therecan be hundreds or thousands of client computing devices 102 continuallygenerating large volumes of primary data 112 to be protected. Also,there can be significant overhead involved in the creation of secondarycopies 116. Moreover, secondary storage devices 108 may be specialpurpose components, and interacting with them can require specializedintelligence.

In some cases, the client computing devices 102 interact directly withthe secondary storage device 108 to create the secondary copies 116.However, in view of the factors described above, this approach cannegatively impact the ability of the client computing devices 102 toserve the applications 110 and produce primary data 112. Further, theclient computing devices 102 may not be optimized for interaction withthe secondary storage devices 108.

Thus, in some embodiments, the information management system 100includes one or more software and/or hardware components which generallyact as intermediaries between the client computing devices 102 and thesecondary storage devices 108. In addition to off-loading certainresponsibilities from the client computing devices 102, theseintermediary components can provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability.

The intermediary components can include one or more secondary storagecomputing devices 106 as shown in FIG. 1A and/or one or more mediaagents, which can be software modules residing on correspondingsecondary storage computing devices 106 (or other appropriate devices).Media agents are discussed below (e.g., with respect to FIGS. 1C-1E).

The secondary storage computing device(s) 106 can comprise anyappropriate type of computing device and can include, withoutlimitation, any of the types of fixed and portable computing devicesdescribed above with respect to the client computing devices 102. Insome cases, the secondary storage computing device(s) 106 includespecialized hardware and/or software componentry for interacting withthe secondary storage devices 108.

To create a secondary copy 116, the client computing device 102communicates the primary data 112 to be copied (or a processed versionthereof) to the designated secondary storage computing device 106, viathe communication pathway 114. The secondary storage computing device106 in turn conveys the received data (or a processed version thereof)to the secondary storage device 108. In some such configurations, thecommunication pathway 114 between the client computing device 102 andthe secondary storage computing device 106 comprises a portion of a LAN,WAN or SAN. In other cases, at least some client computing devices 102communicate directly with the secondary storage devices 108 (e.g., viaFibre Channel or SCSI connections).

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view showing some specific examples of primarydata stored on the primary storage device(s) 104 and secondary copy datastored on the secondary storage device(s) 108, with other components inthe system removed for the purposes of illustration. Stored on theprimary storage device(s) 104 are primary data objects including wordprocessing documents 119A-B, spreadsheets 120, presentation documents122, video files 124, image files 126, email mailboxes 128 (andcorresponding email messages 129A-C), html/xml or other types of markuplanguage files 130, databases 132 and corresponding tables 133A-133C).

Some or all primary data objects are associated with a primary copy ofobject metadata (e.g., “Meta1-11”), which may be file system metadataand/or application specific metadata. Stored on the secondary storagedevice(s) 108 are secondary copy objects 134A-C which may include copiesof or otherwise represent corresponding primary data objects andmetadata.

As shown, the secondary copy objects 134A-C can individually representmore than one primary data object. For example, secondary copy dataobject 134A represents three separate primary data objects 133C, 122 and129C (represented as 133C′, 122′ and 129C′, respectively). Moreover, asindicated by the prime mark (′), a secondary copy object may store arepresentation of a primary data object or metadata differently than theoriginal format, e.g., in a compressed, encrypted, deduplicated, orother modified format.

Exemplary Information Management System Architecture

The information management system 100 can incorporate a variety ofdifferent hardware and software components, which can in turn beorganized with respect to one another in many different configurations,depending on the embodiment. There are critical design choices involvedin specifying the functional responsibilities of the components and therole of each component in the information management system 100. Forinstance, as will be discussed, such design choices can impactperformance as well as the adaptability of the information managementsystem 100 to data growth or other changing circumstances.

FIG. 1C shows an information management system 100 designed according tothese considerations and which includes: a central storage orinformation manager 140 configured to perform certain control functions,one or more data agents 142 executing on the client computing device(s)102 configured to process primary data 112, and one or more media agents144 executing on the one or more secondary storage computing devices 106for performing tasks involving the secondary storage devices 108.

Storage Manager

As noted, the number of components in the information management system100 and the amount of data under management can be quite large. Managingthe components and data is therefore a significant task, and a task thatcan grow in an often unpredictable fashion as the quantity of componentsand data scale to meet the needs of the organization.

For these and other reasons, according to certain embodiments,responsibility for controlling the information management system 100, orat least a significant portion of that responsibility, is allocated tothe storage manager 140.

By distributing control functionality in this manner, the storagemanager 140 can be adapted independently according to changingcircumstances. Moreover, a host computing device can be selected to bestsuit the functions of the storage manager 140. These and otheradvantages are described in further detail below with respect to FIG.1D.

The storage manager 140 may be a software module or other application.The storage manager generally initiates, coordinates and/or controlsstorage and other information management operations performed by theinformation management system 100, e.g., to protect and control theprimary data 112 and secondary copies 116 of data and metadata.

As shown by the dashed, arrowed lines, the storage manager 140 maycommunicate with and/or control some or all elements of the informationmanagement system 100, such as the data agents 142 and media agents 144.Thus, in certain embodiments, control information originates from thestorage manager 140, whereas payload data and metadata is generallycommunicated between the data agents 142 and the media agents 144 (orotherwise between the client computing device(s) 102 and the secondarystorage computing device(s) 106), e.g., at the direction of the storagemanager 140. In other embodiments, some information managementoperations are controlled by other components in the informationmanagement system 100 (e.g., the media agent(s) 144 or data agent(s)142), instead of or in combination with the storage manager 140.

According to certain embodiments, the storage manager provides one ormore of the following functions:

-   -   initiating execution of secondary copy operations;    -   managing secondary storage devices 108 and inventory/capacity of        the same;    -   allocating secondary storage devices 108 for secondary storage        operations;    -   monitoring completion of and providing status reporting related        to secondary storage operations;    -   tracking age information relating to secondary copies 116,        secondary storage devices 108, and comparing the age information        against retention guidelines;    -   tracking movement of data within the information management        system 100;    -   tracking logical associations between components in the        information management system 100;    -   protecting metadata associated with the information management        system 100; and    -   implementing operations management functionality.

The storage manager 140 may maintain a database 146 ofmanagement-related data and information management policies 148. Thedatabase 146 may include a management index 150 or other data structurethat stores logical associations between components of the system, userpreferences and/or profiles (e.g., preferences regarding encryption,compression, or deduplication of primary or secondary copy data,preferences regarding the scheduling, type, or other aspects of primaryor secondary copy or other operations, mappings of particularinformation management users or user accounts to certain computingdevices or other components, etc.), management tasks, mediacontainerization, or other useful data. For example, the storage manager140 may use the index 150 to track logical associations between mediaagents 144 and secondary storage devices 108 and/or movement of datafrom primary storage devices 104 to secondary storage devices 108.

Administrators and other employees may be able to manually configure andinitiate certain information management operations on an individualbasis. But while this may be acceptable for some recovery operations orother relatively less frequent tasks, it is often not workable forimplementing on-going organization-wide data protection and management.

Thus, the information management system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations (e.g., on an automated basis). Generally, aninformation management policy 148 can include a data structure or otherinformation source that specifies a set of parameters (e.g., criteriaand rules) associated with storage or other information managementoperations.

The storage manager database 146 may maintain the information managementpolicies 148 and associated data, although the information managementpolicies 148 can be stored in any appropriate location. For instance, astorage policy may be stored as metadata in a media agent database 152or in a secondary storage device 108 (e.g., as an archive copy) for usein restore operations or other information management operations,depending on the embodiment. Information management policies 148 aredescribed further below.

According to certain embodiments, the storage manager database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding data wereprotected). This and other metadata may additionally be stored in otherlocations, such as at the secondary storage computing devices 106 or onthe secondary storage devices 108, allowing data recovery without theuse of the storage manager 140.

As shown, the storage manager 140 may include a jobs agent 156, a userinterface 158, and a management agent 154, all of which may beimplemented as interconnected software modules or application programs.

The jobs agent 156 in some embodiments initiates, controls, and/ormonitors the status of some or all storage or other informationmanagement operations previously performed, currently being performed,or scheduled to be performed by the information management system 100.For instance, the jobs agent 156 may access information managementpolicies 148 to determine when and how to initiate and control secondarycopy and other information management operations, as will be discussedfurther.

The user interface 158 may include information processing and displaysoftware, such as a graphical user interface (“GUI”), an applicationprogram interface (“API”), or other interactive interface through whichusers and system processes can retrieve information about the status ofinformation management operations (e.g., storage operations) or issueinstructions to the information management system 100 and itsconstituent components.

The storage manager 140 may also track information that permits it toselect, designate, or otherwise identify content indices, deduplicationdatabases, or similar databases or resources or data sets within itsinformation management cell (or another cell) to be searched in responseto certain queries. Such queries may be entered by the user viainteraction with the user interface 158.

Via the user interface 158, users may optionally issue instructions tothe components in the information management system 100 regardingperformance of storage and recovery operations. For example, a user maymodify a schedule concerning the number of pending secondary copyoperations. As another example, a user may employ the GUI to view thestatus of pending storage operations or to monitor the status of certaincomponents in the information management system 100 (e.g., the amount ofcapacity left in a storage device).

In general, the management agent 154 allows multiple informationmanagement systems 100 to communicate with one another. For example, theinformation management system 100 in some cases may be one informationmanagement subsystem or “cell” of a network of multiple cells adjacentto one another or otherwise logically related in a WAN or LAN. With thisarrangement, the cells may be connected to one another throughrespective management agents 154.

For instance, the management agent 154 can provide the storage manager140 with the ability to communicate with other components within theinformation management system 100 (and/or other cells within a largerinformation management system) via network protocols and applicationprogramming interfaces (“APIs”) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs. Inter-cell communication and hierarchy isdescribed in greater detail in U.S. Pat. No. 7,035,880, which isincorporated by reference herein.

Data Agents

As discussed, a variety of different types of applications 110 canreside on a given client computing device 102, including operatingsystems, database applications, e-mail applications, and virtualmachines, just to name a few. And, as part of the as part of the processof creating and restoring secondary copies 116, the client computingdevices 102 may be tasked with processing and preparing the primary data112 from these various different applications 110. Moreover, the natureof the processing/preparation can differ across clients and applicationtypes, e.g., due to inherent structural and formatting differencesbetween applications 110.

The one or more data agent(s) 142 are therefore advantageouslyconfigured in some embodiments to assist in the performance ofinformation management operations based on the type of data that isbeing protected, at a client-specific and/or application-specific level.

The data agent 142 may be a software module or component that isgenerally responsible for managing, initiating, or otherwise assistingin the performance of information management operations. For instance,the data agent 142 may take part in performing data storage operationssuch as the copying, archiving, migrating, replicating of primary data112 stored in the primary storage device(s) 104. The data agent 142 mayreceive control information from the storage manager 140, such ascommands to transfer copies of data objects, metadata, and other payloaddata to the media agents 144.

In some embodiments, a data agent 142 may be distributed between theclient computing device 102 and storage manager 140 (and any otherintermediate components) or may be deployed from a remote location orits functions approximated by a remote process that performs some or allof the functions of data agent 142. In addition, a data agent 142 mayperform some functions provided by a media agent 144, e.g., encryptionand deduplication.

As indicated, each data agent 142 may be specialized for a particularapplication 110, and the system can employ multiple data agents 142,each of which may backup, migrate, and recover data associated with adifferent application 110. For instance, different individual dataagents 142 may be designed to handle Microsoft Exchange data, LotusNotes data, Microsoft Windows file system data, Microsoft ActiveDirectory Objects data, SQL Server data, SharePoint data, Oracledatabase data, SAP database data, virtual machines and/or associateddata, and other types of data.

A file system data agent, for example, may handle data files and/orother file system information. If a client computing device 102 has twoor more types of data, one data agent 142 may be used for each data typeto copy, archive, migrate, and restore the client computing device 102data. For example, to backup, migrate, and restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use oneMicrosoft Exchange Mailbox data agent 142 to backup the Exchangemailboxes, one Microsoft Exchange Database data agent 142 to backup theExchange databases, one Microsoft Exchange Public Folder data agent 142to backup the Exchange Public Folders, and one Microsoft Windows FileSystem data agent 142 to backup the file system of the client computingdevice 102. In such embodiments, these data agents 142 may be treated asfour separate data agents 142 by even though they reside on the sameclient computing device 102.

Other embodiments may employ one or more generic data agents 142 thatcan handle and process data from two or more different applications 110,or that can handle and process multiple data types, instead of or inaddition to using specialized data agents 142. For example, one genericdata agent 142 may be used to back up, migrate and restore MicrosoftExchange Mailbox data and Microsoft Exchange Database data while anothergeneric data agent may handle Microsoft Exchange Public Folder data andMicrosoft Windows File System data.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with the dataagent 142 and process the data as appropriate. For example, during asecondary copy operation, the data agent 142 may arrange or assemble thedata and metadata into one or more files having a certain format (e.g.,a particular backup or archive format) before transferring the file(s)to a media agent 144 or other component. The file(s) may include a listof files or other metadata. Each data agent 142 can also assist inrestoring data or metadata to primary storage devices 104 from asecondary copy 116. For instance, the data agent 142 may operate inconjunction with the storage manager 140 and one or more of the mediaagents 144 to restore data from secondary storage device(s) 108.

Media Agents

As indicated above with respect to FIG. 1A, off-loading certainresponsibilities from the client computing devices 102 to intermediarycomponents such as the media agent(s) 144 can provide a number ofbenefits including improved client computing device 102 operation,faster secondary copy operation performance, and enhanced scalability.As one specific example which will be discussed below in further detail,the media agent 144 can act as a local cache of copied data and/ormetadata that it has stored to the secondary storage device(s) 108,providing improved restore capabilities.

Generally speaking, a media agent 144 may be implemented as a softwaremodule that manages, coordinates, and facilitates the transmission ofdata, as directed by the storage manager 140, between a client computingdevice 102 and one or more secondary storage devices 108. Whereas thestorage manager 140 controls the operation of the information managementsystem 100, the media agent 144 generally provides a portal to secondarystorage devices 108.

Media agents 144 can comprise logically and/or physically separate nodesin the information management system 100 (e.g., separate from the clientcomputing devices 102, storage manager 140, and/or secondary storagedevices 108). In addition, each media agent 144 may reside on adedicated secondary storage computing device 106 in some cases, while inother embodiments a plurality of media agents 144 reside on the samesecondary storage computing device 106.

A media agent 144 (and corresponding media agent database 152) may beconsidered to be “associated with” a particular secondary storage device108 if that media agent 144 is capable of one or more of: routing and/orstoring data to the particular secondary storage device 108,coordinating the routing and/or storing of data to the particularsecondary storage device 108, retrieving data from the particularsecondary storage device 108, and coordinating the retrieval of datafrom a particular secondary storage device 108.

While media agent(s) 144 are generally associated with one or moresecondary storage devices 108, the media agents 144 in certainembodiments are physically separate from the secondary storage devices108. For instance, the media agents 144 may reside on secondary storagecomputing devices 106 having different housings or packages than thesecondary storage devices 108. In one example, a media agent 144 resideson a first server computer and is in communication with a secondarystorage device(s) 108 residing in a separate, rack-mounted RAID-basedsystem.

In operation, a media agent 144 associated with a particular secondarystorage device 108 may instruct the secondary storage device 108 (e.g.,a tape library) to use a robotic arm or other retrieval means to load oreject a certain storage media, and to subsequently archive, migrate, orretrieve data to or from that media, e.g., for the purpose of restoringthe data to a client computing device 102. The media agent 144 maycommunicate with a secondary storage device 108 via a suitablecommunications link, such as a SCSI or Fiber Channel link.

As shown, each media agent 144 may maintain an associated media agentdatabase 152. The media agent database 152 may be stored in a disk orother storage device (not shown) that is local to the secondary storagecomputing device 106 on which the media agent 144 resides. In othercases, the media agent database 152 is stored remotely from thesecondary storage computing device 106.

The media agent database 152 can include, among other things, an index153 including data generated during secondary copy operations and otherstorage or information management operations. The index 153 provides amedia agent 144 or other component with a fast and efficient mechanismfor locating secondary copies 116 or other data stored in the secondarystorage devices 108. In one configuration, a storage manager index 150or other data structure may store data associating a client computingdevice 102 with a particular media agent 144 and/or secondary storagedevice 108, as specified in a storage policy. A media agent index 153 orother data structure associated with the particular media agent 144 mayin turn include information about the stored data.

For instance, for each secondary copy 116, the index 153 may includemetadata such as a list of the data objects (e.g., files/subdirectories,database objects, mailbox objects, etc.), a path to the secondary copy116 on the corresponding secondary storage device 108, locationinformation indicating where the data objects are stored in thesecondary storage device 108, when the data objects were created ormodified, etc. Thus, the index 153 includes metadata associated with thesecondary copies 116 that is readily available for use in storageoperations and other activities without having to be first retrievedfrom the secondary storage device 108. In yet further embodiments, someor all of the data in the index 153 may instead or additionally bestored along with the data in a secondary storage device 108, e.g., witha copy of the index 153.

Because the index 153 maintained in the database 152 may operate as acache, it can also be referred to as an index cache. In such cases,information stored in the index cache 153 typically comprises data thatreflects certain particulars about storage operations that have occurredrelatively recently. After some triggering event, such as after acertain period of time elapses, or the index cache 153 reaches aparticular size, the index cache 153 may be copied or migrated to asecondary storage device(s) 108. This information may need to beretrieved and uploaded back into the index cache 153 or otherwiserestored to a media agent 144 to facilitate retrieval of data from thesecondary storage device(s) 108. In some embodiments, the cachedinformation may include format or containerization information relatedto archives or other files stored on the storage device(s) 108. In thismanner, the index cache 153 allows for accelerated restores.

In some alternative embodiments the media agent 144 generally acts as acoordinator or facilitator of storage operations between clientcomputing devices 102 and corresponding secondary storage devices 108,but does not actually write the data to the secondary storage device108. For instance, the storage manager 140 (or the media agent 144) mayinstruct a client computing device 102 and secondary storage device 108to communicate with one another directly. In such a case the clientcomputing device 102 transmits the data directly to the secondarystorage device 108 according to the received instructions, and viceversa. In some such cases, the media agent 144 may still receive,process, and/or maintain metadata related to the storage operations.Moreover, in these embodiments, the payload data can flow through themedia agent 144 for the purposes of populating the index cache 153maintained in the media agent database 152, but not for writing to thesecondary storage device 108.

The media agent 144 and/or other components such as the storage manager140 may in some cases incorporate additional functionality, such as dataclassification, content indexing, deduplication, encryption,compression, and the like. Further details regarding these and otherfunctions are described below.

Distributed, Scalable Architecture

As described, certain functions of the information management system 100can be distributed amongst various physical and/or logical components inthe system. For instance, one or more of the storage manager 140, dataagents 142, and media agents 144 may reside on computing devices thatare physically separate from one another. This architecture can providea number of benefits.

For instance, hardware and software design choices for each distributedcomponent can be targeted to suit its particular function. The secondarycomputing devices 106 on which the media agents 144 reside can betailored for interaction with associated secondary storage devices 108and provide fast index cache operation, among other specific tasks.Similarly, the client computing device(s) 102 can be selected toeffectively service the applications 110 residing thereon, in order toefficiently produce and store primary data 112.

Moreover, in some cases, one or more of the individual components in theinformation management system 100 can be distributed to multiple,separate computing devices. As one example, for large file systems wherethe amount of data stored in the storage management database 146 isrelatively large, the management database 146 may be migrated to orotherwise reside on a specialized database server (e.g., an SQL server)separate from a server that implements the other functions of thestorage manager 140. This configuration can provide added protectionbecause the database 146 can be protected with standard databaseutilities (e.g., SQL log shipping or database replication) independentfrom other functions of the storage manager 140. The database 146 can beefficiently replicated to a remote site for use in the event of adisaster or other data loss incident at the primary site. Or thedatabase 146 can be replicated to another computing device within thesame site, such as to a higher performance machine in the event that astorage manager host device can no longer service the needs of a growinginformation management system 100.

The distributed architecture also provides both scalability andefficient component utilization. FIG. 1D shows an embodiment of theinformation management system 100 including a plurality of clientcomputing devices 102 and associated data agents 142 as well as aplurality of secondary storage computing devices 106 and associatedmedia agents 144.

Additional components can be added or subtracted based on the evolvingneeds of the information management system 100. For instance, dependingon where bottlenecks are identified, administrators can add additionalclient computing devices 102, secondary storage devices 106 (andcorresponding media agents 144), and/or secondary storage devices 108.

Moreover, each client computing device 102 in some embodiments cancommunicate with any of the media agents 144, e.g., as directed by thestorage manager 140. And each media agent 144 may be able to communicatewith any of the secondary storage devices 108, e.g., as directed by thestorage manager 140. Thus, operations can be routed to the secondarystorage devices 108 in a dynamic and highly flexible manner. Furtherexamples of scalable systems capable of dynamic storage operations areprovided in U.S. Pat. No. 7,246,207, which is incorporated by referenceherein.

In alternative configurations, certain components are not distributedand may instead reside and execute on the same computing device. Forexample, in some embodiments one or more data agents 142 and the storagemanager 140 reside on the same client computing device 102. In anotherembodiment, one or more data agents 142 and one or more media agents 144reside on a single computing device.

Exemplary Types of Information Management Operations

In order to protect and leverage stored data, the information managementsystem 100 can be configured to perform a variety of informationmanagement operations. As will be described, these operations cangenerally include secondary copy and other data movement operations,processing and data manipulation operations, and management operations.

Data Movement Operations

Data movement operations according to certain embodiments are generallyoperations that involve the copying or migration of data (e.g., payloaddata) between different locations in the information management system100. For example, data movement operations can include operations inwhich stored data is copied, migrated, or otherwise transferred fromprimary storage device(s) 104 to secondary storage device(s) 108, fromsecondary storage device(s) 108 to different secondary storage device(s)108, or from primary storage device(s) 104 to different primary storagedevice(s) 104.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication operations),snapshot operations, deduplication operations, single-instancingoperations, auxiliary copy operations, and the like. As will bediscussed, some of these operations involve the copying, migration orother movement of data, without actually creating multiple, distinctcopies. Nonetheless, some or all of these operations are referred to as“copy” operations for simplicity.

Backup Operations

A backup operation creates a copy of primary data 112 at a particularpoint in time. Each subsequent backup copy may be maintainedindependently of the first. Further, a backup copy in some embodimentsis stored in a backup format. This can be in contrast to the version inprimary data 112 from which the backup copy is derived, and which mayinstead be stored in a native format of the source application(s) 110.In various cases, backup copies can be stored in a format in which thedata is compressed, encrypted, deduplicated, and/or otherwise modifiedfrom the original application format. For example, a backup copy may bestored in a backup format that facilitates compression and/or efficientlong-term storage.

Backup copies can have relatively long retention periods as compared toprimary data 112, and may be stored on media with slower retrieval timesthan primary data 112 and certain other types of secondary copies 116.On the other hand, backups may have relatively shorter retention periodsthan some other types of secondary copies 116, such as archive copies(described below). Backups may sometimes be stored at on offsitelocation.

Backup operations can include full, synthetic or incremental backups. Afull backup in some embodiments is generally a complete image of thedata to be protected. However, because full backup copies can consume arelatively large amount of storage, it can be useful to use a fullbackup copy as a baseline and only store changes relative to the fullbackup copy for subsequent backup copies.

For instance, a differential backup operation (or cumulative incrementalbackup operation) tracks and stores changes that have occurred since thelast full backup. Differential backups can grow quickly in size, but canprovide relatively efficient restore times because a restore can becompleted in some cases using only the full backup copy and the latestdifferential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restore times can berelatively long in comparison to full or differential backups becausecompleting a restore operation may involve accessing a full backup inaddition to multiple incremental backups.

Any of the above types of backup operations can be at the file-level,e.g., where the information management system 100 generally trackschanges to files at the file-level, and includes copies of files in thebackup copy. In other cases, block-level backups are employed, wherefiles are broken into constituent blocks, and changes are tracked at theblock-level. Upon restore, the information management system 100reassembles the blocks into files in a transparent fashion.

Far less data may actually be transferred and copied to the secondarystorage devices 108 during a block-level copy than during a file-levelcopy, resulting in faster execution times. However, when restoring ablock-level copy, the process of locating constituent blocks cansometimes result in longer restore times as compared to file-levelbackups. Similar to backup operations, the other types of secondary copyoperations described herein can also be implemented at either thefile-level or the block-level.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied data in primary data 112 and also maintaining backup copies insecondary storage device(s) 108, they can consume significant storagecapacity. To help reduce storage consumption, an archive operationaccording to certain embodiments creates a secondary copy 116 by bothcopying and removing source data. Or, seen another way, archiveoperations can involve moving some or all of the source data to thearchive destination. Thus, data satisfying criteria for removal (e.g.,data of a threshold age or size) from the source copy may be removedfrom source storage. Archive copies are sometimes stored in an archiveformat or other non-native application format. The source data may beprimary data 112 or a secondary copy 116, depending on the situation. Aswith backup copies, archive copies can be stored in a format in whichthe data is compressed, encrypted, deduplicated, and/or otherwisemodified from the original application format.

In addition, archive copies may be retained for relatively long periodsof time (e.g., years) and, in some cases, are never deleted. Archivecopies are generally retained for longer periods of time than backupcopies, for example. In certain embodiments, archive copies may be madeand kept for extended periods in order to meet compliance regulations.

Moreover, when primary data 112 is archived, in some cases the archivedprimary data 112 or a portion thereof is deleted when creating thearchive copy. Thus, archiving can serve the purpose of freeing up spacein the primary storage device(s) 104. Similarly, when a secondary copy116 is archived, the secondary copy 116 may be deleted, and an archivecopy can therefore serve the purpose of freeing up space in secondarystorage device(s) 108. In contrast, source copies often remain intactwhen creating backup copies.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of the primary data 112 at agiven point in time. In one embodiment, a snapshot may generally capturethe directory structure of an object in primary data 112 such as a fileor volume or other data set at a particular moment in time and may alsopreserve file attributes and contents. A snapshot in some cases iscreated relatively quickly, e.g., substantially instantly, using aminimum amount of file space, but may still function as a conventionalfile system backup.

A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that are able to map files and directories tospecific memory locations (e.g., disk blocks) where the data resides, asit existed at the particular point in time. For example, a snapshot copymay include a set of pointers derived from the file system or anapplication. Each pointer points to a respective stored data block, socollectively, the set of pointers reflect the storage location and stateof the data object (e.g., file(s) or volume(s) or data set(s)) at aparticular point in time when the snapshot copy was created.

In some embodiments, once a snapshot has been taken, subsequent changesto the file system typically do not overwrite the blocks in use at thetime of the snapshot. Therefore, the initial snapshot may use only asmall amount of disk space needed to record a mapping or other datastructure representing or otherwise tracking the blocks that correspondto the current state of the file system. Additional disk space isusually required only when files and directories are actually modifiedlater. Furthermore, when files are modified, typically only the pointerswhich map to blocks are copied, not the blocks themselves. In someembodiments, for example in the case of “copy-on-write” snapshots, whena block changes in primary storage, the block is copied to secondarystorage or cached in primary storage before the block is overwritten inprimary storage. The snapshot mapping of file system data is alsoupdated to reflect the changed block(s) at that particular point intime. In some other cases, a snapshot includes a full physical copy ofall or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782, which is incorporated by reference herein.

Replication Operations

Another type of secondary copy operation is a replication operation.Some types of secondary copies 116 are used to periodically captureimages of primary data 112 at particular points in time (e.g., backups,archives, and snapshots). However, it can also be useful for recoverypurposes to protect primary data 112 in a more continuous fashion, byreplicating the primary data 112 substantially as changes occur. In somecases a replication copy can be a mirror copy, for instance, wherechanges made to primary data 112 are mirrored to another location (e.g.,to secondary storage device(s) 108). By copying each write operation tothe replication copy, two storage systems are kept synchronized orsubstantially synchronized so that they are virtually identical atapproximately the same time. Where entire disk volumes are mirrored,however, mirroring can require significant amount of storage space andutilizes a large amount of processing resources.

According to some embodiments storage operations are performed onreplicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, backup or otherwise manipulate thereplication copies as if the data was the “live”, primary data 112. Thiscan reduce access time, storage utilization, and impact on sourceapplications 110, among other benefits.

Based on known good state information, the information management system100 can replicate sections of application data that represent arecoverable state rather than rote copying of blocks of data. Examplesof compatible replication operations (e.g., continuous data replication)are provided in U.S. Pat. No. 7,617,262, which is incorporated byreference herein.

Deduplication/Single-Instancing Operations

Another type of data movement operation is deduplication, which isuseful to reduce the amount of data within the system. For instance,some or all of the above-described secondary storage operations caninvolve deduplication in some fashion. New data is read, broken downinto blocks (e.g., sub-file level blocks) of a selected granularity,compared with blocks that are already stored, and only the new blocksare stored. Blocks that already exist are represented as pointers to thealready stored data.

In order to stream-line the comparison process, the informationmanagement system 100 may calculate and/or store signatures (e.g.,hashes) corresponding to the individual data blocks and compare thehashes instead of comparing entire data blocks. In some cases, only asingle instance of each element is stored, and deduplication operationsmay therefore be referred to interchangeably as “single-instancing”operations. Depending on the implementation, however, deduplication orsingle-instancing operations can store more than one instance of certaindata blocks, but nonetheless significantly reduce data redundancy.Moreover, single-instancing in some cases is distinguished fromdeduplication as a process of analyzing and reducing data at the filelevel, rather than the sub-file level.

Depending on the embodiment, deduplication blocks can be of fixed orvariable length. Using variable length blocks can provide enhanceddeduplication by responding to changes in the data stream, but caninvolve complex processing. In some cases, the information managementsystem 100 utilizes a technique for dynamically aligning deduplicationblocks (e.g., fixed-length blocks) based on changing content in the datastream, as described in U.S. Pat. Pub. No. 2012/0084268, which isincorporated by reference herein.

The information management system 100 can perform deduplication in avariety of manners at a variety of locations in the informationmanagement system 100. For instance, in some embodiments, theinformation management system 100 implements “target-side” deduplicationby deduplicating data (e.g., secondary copies 116) stored in thesecondary storage devices 108. In some such cases, the media agents 144are generally configured to manage the deduplication process. Forinstance, one or more of the media agents 144 maintain a correspondingdeduplication database that stores deduplication information (e.g.,datablock signatures). Examples of such a configuration are provided inU.S. Pat. Pub. No. 2012/0150826, which is incorporated by referenceherein. Deduplication can also be performed on the “source-side” (or“client-side”), e.g., to reduce the amount of traffic between the mediaagents 144 and the client computing device(s) 102 and/or reduceredundant data stored in the primary storage devices 104. Examples ofsuch deduplication techniques are provided in U.S. Pat. Pub. No.2012/0150818, which is incorporated by reference herein.

Information Lifecycle Management and Hierarchical Storage ManagementOperations

In some embodiments, files and other data over their lifetime move frommore expensive, quick access storage to less expensive, slower accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation. A HSM operation is generally an operation for automaticallymoving data between classes of storage devices, such as betweenhigh-cost and low-cost storage devices. For instance, an HSM operationmay involve movement of data from primary storage devices 104 tosecondary storage devices 108, or between tiers of secondary storagedevices 108. With each tier, the storage devices may be progressivelyrelatively cheaper, have relatively slower access/restore times, etc.For example, movement of data between tiers may occur as data becomesless important over time.

In some embodiments, an HSM operation is similar to an archive operationin that creating an HSM copy may (though not always) involve deletingsome of the source data. For example, an HSM copy may include data fromprimary data 112 or a secondary copy 116 that is larger than a givensize threshold or older than a given age threshold and that is stored ina backup format.

Often, and unlike some types of archive copies, HSM data that is removedor aged from the source copy is replaced by a logical reference pointeror stub. The reference pointer or stub can be stored in the primarystorage device 104 to replace the deleted data in primary data 112 (orother source copy) and to point to or otherwise indicate the newlocation in a secondary storage device 108.

According to one example, files are generally moved between higher andlower cost storage depending on how often the files are accessed. When auser requests access to the HSM data that has been removed or migrated,the information management system 100 uses the stub to locate the dataand often make recovery of the data appear transparent, even though theHSM data may be stored at a location different from the remaining sourcedata. The stub may also include some metadata associated with thecorresponding data, so that a file system and/or application can providesome information about the data object and/or a limited-functionalityversion (e.g., a preview) of the data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., where the data is compressed, encrypted, deduplicated,and/or otherwise modified from the original application format). In somecases, copies which involve the removal of data from source storage andthe maintenance of stub or other logical reference information on sourcestorage may be referred to generally as “on-line archive copies”. On theother hand, copies which involve the removal of data from source storagewithout the maintenance of stub or other logical reference informationon source storage may be referred to as “off-line archive copies”.

Auxiliary Copy and Disaster Recovery Operations

An auxiliary copy is generally a copy operation in which a copy iscreated of an existing secondary copy 116. For instance, an initial or“primary” secondary copy 116 may be generated using or otherwise bederived from primary data 112, whereas an auxiliary copy is generatedfrom the initial secondary copy 116. Auxiliary copies can be used tocreate additional standby copies of data and may reside on differentsecondary storage devices 108 than initial secondary copies 116. Thus,auxiliary copies can be used for recovery purposes if initial secondarycopies 116 become unavailable. Exemplary compatible auxiliary copytechniques are described in further detail in U.S. Pat. No. 8,230,195,which is incorporated by reference herein.

The information management system 100 may also perform disaster recoveryoperations that make or retain disaster recovery copies, often assecondary, high-availability disk copies. The information managementsystem 100 may create secondary disk copies and store the copies atdisaster recovery locations using auxiliary copy or replicationoperations, such as continuous data replication technologies. Dependingon the particular data protection goals, disaster recovery locations canbe remote from the client computing devices 102 and primary storagedevices 104, remote from some or all of the secondary storage devices108, or both.

Data Processing and Manipulation Operations

As indicated, the information management system 100 can also beconfigured to implement certain data manipulation operations, whichaccording to certain embodiments are generally operations involving theprocessing or modification of stored data. Some data manipulationoperations include content indexing operations and classificationoperations can be useful in leveraging the data under management toprovide enhanced search and other features. Other data manipulationoperations such as compression and encryption can provide data reductionand security benefits, respectively.

Data manipulation operations can be different than data movementoperations in that they do not necessarily involve the copying,migration or other transfer of data (e.g., primary data 112 or secondarycopies 116) between different locations in the system. For instance,data manipulation operations may involve processing (e.g., offlineprocessing) or modification of already stored primary data 112 and/orsecondary copies 116. However, in some embodiments data manipulationoperations are performed in conjunction with data movement operations.As one example, the information management system 100 may encrypt datawhile performing an archive operation.

Content Indexing

In some embodiments, the information management system 100 “contentindexes” data stored within the primary data 112 and/or secondary copies116, providing enhanced search capabilities for data discovery and otherpurposes. The content indexing can be used to identify files or otherdata objects having pre-defined content (e.g., user-defined keywords orphrases), metadata (e.g., email metadata such as “to”, “from”, “cc”,“bcc”, attachment name, received time, etc.).

The information management system 100 generally organizes and cataloguesthe results in a content index, which may be stored within the mediaagent database 152, for example. The content index can also include thestorage locations of (or pointer references to) the indexed data in theprimary data 112 or secondary copies 116, as appropriate. The resultsmay also be stored, in the form of a content index database orotherwise, elsewhere in the information management system 100 (e.g., inthe primary storage devices 104, or in the secondary storage device108). Such index data provides the storage manager 140 or anothercomponent with an efficient mechanism for locating primary data 112and/or secondary copies 116 of data objects that match particularcriteria.

For instance, search criteria can be specified by a user through userinterface 158 of the storage manager 140. In some cases, the informationmanagement system 100 analyzes data and/or metadata in secondary copies116 to create an “off-line” content index, without significantlyimpacting the performance of the client computing devices 102. Dependingon the embodiment, the system can also implement “on-line” contentindexing, e.g., of primary data 112. Examples of compatible contentindexing techniques are provided in U.S. Pat. No. 8,170,995, which isincorporated by reference herein.

Classification Operations—Metabase

In order to help leverage the data stored in the information managementsystem 100, one or more components can be configured to scan data and/orassociated metadata for classification purposes to populate a metabaseof information. Such scanned, classified data and/or metadata may beincluded in a separate database and/or on a separate storage device fromprimary data 112 (and/or secondary copies 116), such that metabaserelated operations do not significantly impact performance on othercomponents in the information management system 100.

In other cases, the metabase(s) may be stored along with primary data112 and/or secondary copies 116. Files or other data objects can beassociated with user-specified identifiers (e.g., tag entries) in themedia agent 144 (or other indices) to facilitate searches of stored dataobjects. Among a number of other benefits, the metabase can also allowefficient, automatic identification of files or other data objects toassociate with secondary copy or other information management operations(e.g., in lieu of scanning an entire file system). Examples ofcompatible metabases and data classification operations are provided inU.S. Pat. Nos. 8,229,954 and 7,747,579, which are incorporated byreference herein.

Encryption Operations

The information management system 100 in some cases is configured toprocess data (e.g., files or other data objects, secondary copies 116,etc.), according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard [AES], Triple Data Encryption Standard[3-DES], etc.) to limit access and provide data security in theinformation management system 100.

The information management system 100 in some cases encrypts the data atthe client level, such that the client computing devices 102 (e.g., thedata agents 142) encrypt the data prior to forwarding the data to othercomponents, e.g., before sending the data media agents 144 during asecondary copy operation. In such cases, the client computing device 102may maintain or have access to an encryption key or passphrase fordecrypting the data upon restore. Encryption can also occur whencreating copies of secondary copies, e.g., when creating auxiliarycopies. In yet further embodiments, the secondary storage devices 108can implement built-in, high performance hardware encryption.

Management Operations

Certain embodiments leverage the integrated, ubiquitous nature of theinformation management system 100 to provide useful system-widemanagement functions. As two non-limiting examples, the informationmanagement system 100 can be configured to implement operationsmanagement and e-discovery functions.

Operations management can generally include monitoring and managing thehealth and performance of information management system 100 by, withoutlimitation, performing error tracking, generating granularstorage/performance metrics (e.g., job success/failure information,deduplication efficiency, etc.), generating storage modeling and costinginformation, and the like.

Such information can be provided to users via the user interface 158 ina single, integrated view. For instance, the integrated user interface158 can include an option to show a “virtual view” of the system thatgraphically depicts the various components in the system usingappropriate icons. The operations management functionality canfacilitate planning and decision-making. For example, in someembodiments, a user may view the status of some or all jobs as well asthe status of each component of the information management system 100.Users may then plan and make decisions based on this data. For instance,a user may view high-level information regarding storage operations forthe information management system 100, such as job status, componentstatus, resource status (e.g., network pathways, etc.), and otherinformation. The user may also drill down or use other means to obtainmore detailed information regarding a particular component, job, or thelike.

In some cases the information management system 100 alerts a user suchas a system administrator when a particular resource is unavailable orcongested. For example, a particular primary storage device 104 orsecondary storage device 108 might be full or require additionalcapacity. Or a component may be unavailable due to hardware failure,software problems, or other reasons. In response, the informationmanagement system 100 may suggest solutions to such problems when theyoccur (or provide a warning prior to occurrence). For example, thestorage manager 140 may alert the user that a secondary storage device108 is full or otherwise congested. The storage manager 140 may thensuggest, based on job and data storage information contained in itsdatabase 146, an alternate secondary storage device 108.

Other types of corrective actions may include suggesting an alternatedata path to a particular primary or secondary storage device 104, 108,or dividing data to be stored among various available primary orsecondary storage devices 104, 108 as a load balancing measure or tootherwise optimize storage or retrieval time. Such suggestions orcorrective actions may be performed automatically, if desired. Furtherexamples of some compatible operations management techniques and ofinterfaces providing an integrated view of an information managementsystem are provided in U.S. Pat. No. 7,343,453, which is incorporated byreference herein. In some embodiments, the storage manager 140implements the operations management functions described herein.

The information management system 100 can also be configured to performsystem-wide e-discovery operations in some embodiments. In general,e-discovery operations provide a unified collection and searchcapability for data in the system, such as data stored in the secondarystorage devices 108 (e.g., backups, archives, or other secondary copies116). For example, the information management system 100 may constructand maintain a virtual repository for data stored in the informationmanagement system 100 that is integrated across source applications 110,different storage device types, etc. According to some embodiments,e-discovery utilizes other techniques described herein, such as dataclassification and/or content indexing.

Information Management Policies

As indicated previously, an information management policy 148 caninclude a data structure or other information source that specifies aset of parameters (e.g., criteria and rules) associated with secondarycopy or other information management operations.

One type of information management policy 148 is a storage policy.According to certain embodiments, a storage policy generally comprises alogical container that defines (or includes information sufficient todetermine) one or more of the following items: (1) what data will beassociated with the storage policy; (2) a destination to which the datawill be stored; (3) datapath information specifying how the data will becommunicated to the destination; (4) the type of storage operation to beperformed; and (5) retention information specifying how long the datawill be retained at the destination.

Data associated with a storage policy can be logically organized intogroups, which can be referred to as “sub-clients”. A sub-client mayrepresent static or dynamic associations of portions of a data volume.Sub-clients may represent mutually exclusive portions. Thus, in certainembodiments, a portion of data may be given a label and the associationis stored as a static entity in an index, database or other storagelocation.

Sub-clients may also be used as an effective administrative scheme oforganizing data according to data type, department within theenterprise, storage preferences, or the like. Depending on theconfiguration, sub-clients can correspond to files, folders, virtualmachines, databases, etc. In one exemplary scenario, an administratormay find it preferable to separate e-mail data from financial data usingtwo different sub-clients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the sub-clients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the sub-clients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesub-client data.

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data (e.g., one or more sub-clients) associated withthe storage policy between the source (e.g., one or more host clientcomputing devices 102) and destination (e.g., a particular targetsecondary storage device 108).

A storage policy can also specify the type(s) of operations associatedwith the storage policy, such as a backup, archive, snapshot, auxiliarycopy, or the like. Retention information can specify how long the datawill be kept, depending on organizational needs (e.g., a number of days,months, years, etc.)

The information management policies 148 may also include one or morescheduling policies specifying when and how often to perform operations.Scheduling information may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations will takeplace. Scheduling policies in some cases are associated with particularcomponents, such as particular sub-clients, client computing device 102,and the like. In one configuration, a separate scheduling policy ismaintained for particular sub-clients on a client computing device 102.The scheduling policy specifies that those sub-clients are to be movedto secondary storage devices 108 every hour according to storagepolicies associated with the respective sub-clients.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via the user interface 158. However, this can be aninvolved process resulting in delays, and it may be desirable to begindata protecting operations quickly.

Thus, in some embodiments, the information management system 100automatically applies a default configuration to client computing device102. As one example, when a data agent(s) 142 is installed on a clientcomputing devices 102, the installation script may register the clientcomputing device 102 with the storage manager 140, which in turn appliesthe default configuration to the new client computing device 102. Inthis manner, data protection operations can begin substantiallyimmediately. The default configuration can include a default storagepolicy, for example, and can specify any appropriate informationsufficient to begin data protection operations. This can include a typeof data protection operation, scheduling information, a target secondarystorage device 108, data path information (e.g., a particular mediaagent 144), and the like.

Other types of information management policies 148 are possible. Forinstance, the information management policies 148 can also include oneor more audit or security policies. An audit policy is a set ofpreferences, rules and/or criteria that protect sensitive data in theinformation management system 100. For example, an audit policy maydefine “sensitive objects” as files or objects that contain particularkeywords (e.g. “confidential,” or “privileged”) and/or are associatedwith particular keywords (e.g., in metadata) or particular flags (e.g.,in metadata identifying a document or email as personal, confidential,etc.).

An audit policy may further specify rules for handling sensitiveobjects. As an example, an audit policy may require that a reviewerapprove the transfer of any sensitive objects to a cloud storage site,and that if approval is denied for a particular sensitive object, thesensitive object should be transferred to a local storage device 104instead. To facilitate this approval, the audit policy may furtherspecify how a secondary storage computing device 106 or other systemcomponent should notify a reviewer that a sensitive object is slated fortransfer.

In some implementations, the information management policies 148 mayinclude one or more provisioning policies. A provisioning policy caninclude a set of preferences, priorities, rules, and/or criteria thatspecify how clients 102 (or groups thereof) may utilize systemresources, such as available storage on cloud storage and/or networkbandwidth. A provisioning policy specifies, for example, data quotas forparticular client computing devices 102 (e.g. a number of gigabytes thatcan be stored monthly, quarterly or annually). The storage manager 140or other components may enforce the provisioning policy. For instance,the media agents 144 may enforce the policy when transferring data tosecondary storage devices 108. If a client computing device 102 exceedsa quota, a budget for the client computing device 102 (or associateddepartment) is adjusted accordingly or an alert may trigger.

While the above types of information management policies 148 have beendescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies. Moreover, whilestorage policies are typically associated with moving and storing data,other policies may be associated with other types of informationmanagement operations. The following is a non-exhaustive list of itemsthe information management policies 148 may specify:

-   -   schedules or other timing information, e.g., specifying when        and/or how often to perform information management operations;    -   the type of secondary copy 116 and/or secondary copy format        (e.g., snapshot, backup, archive, HSM, etc.);    -   a location or a class or quality of storage for storing        secondary copies 116 (e.g., one or more particular secondary        storage devices 108);    -   preferences regarding whether and how to encrypt, compress,        deduplicate, or otherwise modify or transform secondary copies        116;    -   which system components and/or network pathways (e.g., preferred        media agents 144) should be used to perform secondary storage        operations;    -   resource allocation between different computing devices or other        system components used in performing information management        operations (e.g., bandwidth allocation, available storage        capacity, etc.);    -   whether and how to synchronize or otherwise distribute files or        other data objects across multiple computing devices or hosted        services; and    -   retention information specifying the length of time primary data        112 and/or secondary copies 116 should be retained, e.g., in a        particular class or tier of storage devices, or within the        information management system 100.

Policies can additionally specify or depend on a variety of historicalor current criteria that may be used to determine which rules to applyto a particular data object, system component, or information managementoperation, such as:

-   -   frequency with which primary data 112 or a secondary copy 116 of        a data object or metadata has been or is predicted to be used,        accessed, or modified;    -   time-related factors (e.g., aging information such as time since        the creation or modification of a data object);    -   deduplication information (e.g., hashes, data blocks,        deduplication block size, deduplication efficiency or other        metrics);    -   an estimated or historic usage or cost associated with different        components (e.g., with secondary storage devices 108);    -   the identity of users, applications 110, client computing        devices 102 and/or other computing devices that created,        accessed, modified, or otherwise utilized primary data 112 or        secondary copies 116;    -   a relative sensitivity (e.g., confidentiality) of a data object,        e.g., as determined by its content and/or metadata;    -   the current or historical storage capacity of various storage        devices;    -   the current or historical network capacity of network pathways        connecting various components within the storage operation cell;    -   access control lists or other security information; and    -   the content of a particular data object (e.g., its textual        content) or of metadata associated with the data object.        Exemplary Storage Policy and Secondary Storage Operations

FIG. 1E shows a data flow data diagram depicting performance of storageoperations by an embodiment of an information management system 100,according to an exemplary data storage policy 148A. The informationmanagement system 100 includes a storage manger 140, a client computingdevice 102 having a file system data agent 142A and an email data agent142B residing thereon, a primary storage device 104, two media agents144A, 144B, and two secondary storage devices 108A, 108B: a disk library108A and a tape library 108B. As shown, the primary storage device 104includes primary data 112A, 112B associated with a file systemsub-client and an email sub-client, respectively.

As indicated by the dashed box, the second media agent 144B and the tapelibrary 108B are “off-site”, and may therefore be remotely located fromthe other components in the information management system 100 (e.g., ina different city, office building, etc.). In this manner, informationstored on the tape library 108B may provide protection in the event of adisaster or other failure.

The file system sub-client and its associated primary data 112A incertain embodiments generally comprise information generated by the filesystem and/or operating system of the client computing device 102, andcan include, for example, file system data (e.g., regular files, filetables, mount points, etc.), operating system data (e.g., registries,event logs, etc.), and the like. The e-mail sub-client, on the otherhand, and its associated primary data 112B, include data generated by ane-mail client application operating on the client computing device 102,and can include mailbox information, folder information, emails,attachments, associated database information, and the like. As describedabove, the sub-clients can be logical containers, and the data includedin the corresponding primary data 112A, 112B may or may not be storedcontiguously.

The exemplary storage policy 148A includes a backup copy rule set 160, adisaster recovery copy rule set 162, and a compliance copy rule set 164.The backup copy rule set 160 specifies that it is associated with a filesystem sub-client 166 and an email sub-client 168. Each of thesesub-clients 166, 168 are associated with the particular client computingdevice 102. The backup copy rule set 160 further specifies that thebackup operation will be written to the disk library 108A, anddesignates a particular media agent 144A to convey the data to the disklibrary 108A. Finally, the backup copy rule set 160 specifies thatbackup copies created according to the rule set 160 are scheduled to begenerated on an hourly basis and to be retained for 30 days. In someother embodiments, scheduling information is not included in the storagepolicy 148A, and is instead specified by a separate scheduling policy.

The disaster recovery copy rule set 162 is associated with the same twosub-clients 166, 168. However, the disaster recovery copy rule set 162is associated with the tape library 108B, unlike the backup copy ruleset 160. Moreover, the disaster recovery copy rule set 162 specifiesthat a different media agent 144B than the media agent 144A associatedwith the backup copy rule set 160 will be used to convey the data to thetape library 108B. As indicated, disaster recovery copies createdaccording to the rule set 162 will be retained for 60 days, and will begenerated on a daily basis. Disaster recovery copies generated accordingto the disaster recovery copy rule set 162 can provide protection in theevent of a disaster or other data-loss event that would affect thebackup copy 116A maintained on the disk library 108A.

The compliance copy rule set 164 is only associated with the emailsub-client 166, and not the file system sub-client 168. Compliancecopies generated according to the compliance copy rule set 164 willtherefore not include primary data 112A from the file system sub-client166. For instance, the organization may be under an obligation to storemaintain copies of email data for a particular period of time (e.g., 10years) to comply with state or federal regulations, while similarregulations do not apply to the file system data. The compliance copyrule set 164 is associated with the same tape library 108B and mediaagent 144B as the disaster recovery copy rule set 162, although adifferent storage device or media agent could be used in otherembodiments. Finally, the compliance copy rule set 164 specifies thatcopies generated under the compliance copy rule set 164 will be retainedfor 10 years, and will be generated on a quarterly basis.

At step 1, the storage manager 140 initiates a backup operationaccording to the backup copy rule set 160. For instance, a schedulingservice running on the storage manager 140 accesses schedulinginformation from the backup copy rule set 160 or a separate schedulingpolicy associated with the client computing device 102, and initiates abackup copy operation on an hourly basis. Thus, at the scheduled timeslot the storage manager 140 sends instructions to the client computingdevice 102 to begin the backup operation.

At step 2, the file system data agent 142A and the email data agent 142Bresiding on the client computing device 102 respond to the instructionsreceived from the storage manager 140 by accessing and processing theprimary data 112A, 112B involved in the copy operation from the primarystorage device 104. Because the operation is a backup copy operation,the data agent(s) 142A, 142B may format the data into a backup format orotherwise process the data.

At step 3, the client computing device 102 communicates the retrieved,processed data to the first media agent 144A, as directed by the storagemanager 140, according to the backup copy rule set 160. In some otherembodiments, the information management system 100 may implement aload-balancing, availability-based, or other appropriate algorithm toselect from the available set of media agents 144A, 144B. Regardless ofthe manner the media agent 144A is selected, the storage manager 140 mayfurther keep a record in the storage manager database 140 of theassociation between the selected media agent 144A and the clientcomputing device 102 and/or between the selected media agent 144A andthe backup copy 116A.

The target media agent 144A receives the data from the client computingdevice 102, and at step 4 conveys the data to the disk library 108A tocreate the backup copy 116A, again at the direction of the storagemanager 140 and according to the backup copy rule set 160. The secondarystorage device 108A can be selected in other ways. For instance, themedia agent 144A may have a dedicated association with a particularsecondary storage device(s), or the storage manager 140 or media agent144A may select from a plurality of secondary storage devices, e.g.,according to availability, using one of the techniques described in U.S.Pat. No. 7,246,207, which is incorporated by reference herein.

The media agent 144A can also update its index 153 to include dataand/or metadata related to the backup copy 116A, such as informationindicating where the backup copy 116A resides on the disk library 108A,data and metadata for cache retrieval, etc. After the 30 day retentionperiod expires, the storage manager 140 instructs the media agent 144Ato delete the backup copy 116A from the disk library 108A.

At step 5, the storage manager 140 initiates the creation of a disasterrecovery copy 116B according to the disaster recovery copy rule set 162.For instance, at step 6, based on instructions received from the storagemanager 140 at step 5, the specified media agent 144B retrieves the mostrecent backup copy 116A from the disk library 108A.

At step 7, again at the direction of the storage manager 140 and asspecified in the disaster recovery copy rule set 162, the media agent144B uses the retrieved data to create a disaster recovery copy 116B onthe tape library 108B. In some cases, the disaster recovery copy 116B isa direct, mirror copy of the backup copy 116A, and remains in the backupformat. In other embodiments, the disaster recovery copy 116C may begenerated in some other manner, such as by using the primary data 112A,112B from the storage device 104 as source data. The disaster recoverycopy operation is initiated once a day and the disaster recovery copies116A are deleted after 60 days.

At step 8, the storage manager 140 initiates the creation of acompliance copy 116C, according to the compliance copy rule set 164. Forinstance, the storage manager 140 instructs the media agent 144B tocreate the compliance copy 116C on the tape library 108B at step 9, asspecified in the compliance copy rule set 164. In the example, thecompliance copy 116C is generated using the disaster recovery copy 116B.In other embodiments, the compliance copy 116C is instead generatedusing either the primary data 112B corresponding to the email sub-clientor using the backup copy 116A from the disk library 108A as source data.As specified, compliance copies 116C are created quarterly, and aredeleted after ten years.

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of the secondary copies116A, 116B, 116C. As one example, a user may manually initiate a restoreof the backup copy 116A by interacting with the user interface 158 ofthe storage manager 140. The storage manager 140 then accesses data inits index 150 (and/or the respective storage policy 148A) associatedwith the selected backup copy 116A to identify the appropriate mediaagent 144A and/or secondary storage device 116A.

In other cases, a media agent may be selected for use in the restoreoperation based on a load balancing algorithm, an availability basedalgorithm, or other criteria. The selected media agent 144A retrievesthe data from the disk library 108A. For instance, the media agent 144Amay access its index 153 to identify a location of the backup copy 116Aon the disk library 108A, or may access location information residing onthe disk 108A itself.

When the backup copy 116A was recently created or accessed, the mediaagent 144A accesses a cached version of the backup copy 116A residing inthe media agent index 153, without having to access the disk library108A for some or all of the data. Once it has retrieved the backup copy116A, the media agent 144A communicates the data to the source clientcomputing device 102. Upon receipt, the file system data agent 142A andthe email data agent 142B may unpackage (e.g., restore from a backupformat to the native application format) the data in the backup copy116A and restore the unpackaged data to the primary storage device 104.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary, dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512 MB, 1 GB, 2 GB, 4GB, or 8 GB chunks). This can facilitate efficient communication andwriting to secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to a single secondary storage device 108 oracross multiple secondary storage devices 108. In some cases, users canselect different chunk sizes, e.g., to improve throughput to tapestorage devices.

Generally, each chunk can include a header and a payload. The payloadcan include files (or other data units) or subsets thereof included inthe chunk, whereas the chunk header generally includes metadata relatingto the chunk, some or all of which may be derived from the payload. Forexample, during a secondary copy operation, the media agent 144, storagemanager 140, or other component may divide the associated files intochunks and generate headers for each chunk by processing the constituentfiles.

The headers can include a variety of information such as fileidentifier(s), volume(s), offset(s), or other information associatedwith the payload data items, a chunk sequence number, etc. Importantly,in addition to being stored with the secondary copy 116 on the secondarystorage device 108, the chunk headers can also be stored to the index153 of the associated media agent(s) 144 and/or the storage managerindex 150. This is useful in some cases for providing faster processingof secondary copies 116 during restores or other operations. In somecases, once a chunk is successfully transferred to a secondary storagedevice 108, the secondary storage device 108 returns an indication ofreceipt, e.g., to the media agent 144 and/or storage manager 140, whichmay update their respective indexes 150, 153 accordingly.

During restore, chunks may be processed (e.g., by the media agent 144)according to the information in the chunk header to reassemble thefiles. Additional information relating to chunks can be found in U.S.Pat. No. 8,156,086, which is incorporated by reference herein.

System Overview

The systems and methods described with respect to FIGS. 1A-1E can beused for archiving and restoring virtual machines and their associateddata. In some embodiments, a virtual machine archiving module is asoftware module that forms a part of or resides on the storage manager140 or, alternatively, the media agents 144. The virtual machinearchiving module can additionally be a software module executing on oneor more of the client computers 102. In some embodiments, the virtualmachine archiving module may be implemented as a part of the data agent142. Virtual machine archiving and seamless virtual machine recall willbe discussed in more detail with respect to FIGS. 2-5.

An Exemplary Data Storage System for Implementing Virtual MachineArchiving and Virtual Machine Seamless Restore

FIG. 2 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary storage system 200 configured toarchive virtual machines according to certain embodiments. Asillustrated, the exemplary data storage system 200 includes a storagemanager 210, one or more clients 220, one or more information stores230, a virtual machine (VM) archiving module 250, one or more mediaagents 270, and one or more secondary storage devices 280. A client 220may include a hypervisor 227 and one or more virtual machines (VMs) 225.The system 200 and corresponding components of FIG. 2 may be similar toor the same as the system 100 and similarly named components of FIG. 1D.Moreover, depending on the embodiment, the system 200 of FIG. 2 mayadditionally include any of the other components shown in FIG. 1D thatare not specifically shown in FIG. 2 (e.g., one or more data agents, oneor more applications, etc.). The system 200 may include one or more ofeach component. All components of the system 200 can be in directcommunication with each other or communicate indirectly via the client220, the storage manager 210, the media agent 270, or the like. Incertain embodiments, some of the components in FIG. 2 shown as separatecomponents can reside on a single computing device, or vice versa. Forexample, the virtual machine archiving module 250 can be on the storagemanager 210 or on a separate computing device.

The term virtualization in the computing arts can refer to the creationof a virtual instance of an entity (e.g., a hardware platform, operatingsystem, storage device or network resource, etc.) that behaves like aphysical instance. For instance, a virtual machine can be a softwarerepresentation of a physical machine. Enterprises may use virtualizationfor a variety of purposes, such as to reduce the number of physicalservers or other computers by instantiating multiple virtual machines ona single physical host computer. In this manner, virtualization can beused to centralize administrative tasks while improving scalability andworkloads, and can be an important tool for maximizing hardwareutilization.

Using virtualization techniques, many (e.g., hundreds or thousands) ofvirtual machines can be instantiated on a single host device. The hostdevice can contain significant amounts of memory and computing power inorder to execute the virtual machines, which can be referred to as“clients” or “guests.” Although each virtual client can be logicallyviewed as a stand-alone device, in actuality the virtual client machinesshare underlying hardware with the other virtual machines residing onthe host.

With further reference to FIG. 2, the interaction between the variouscomponents of the exemplary data storage system will now be described ingreater detail with respect to data flow steps indicated by the numberedarrows.

At data flow step 1, the virtual machine archiving module 250 determineswhether a virtual machine 225 is low usage. The VM archiving module 250may be a part of the storage manager 210 or may be on a separatecomputing device. One or more virtual machines 225 may run on one ormore client computers 227. For instance, multiple virtual machines 225can execute on one client computer 220, as shown in FIG. 2. In someembodiments, one virtual machine 225 can execute on multiple clientcomputers 220. Each client 220 may include a hypervisor 227 thatcontrols and manages the one or more virtual machines 225 on the client220. The information store 230 associated with the client 220 may storeinformation and/or data related to the virtual machine(s) 225 on theclient 220. In some embodiments, a virtual center manages and collectsinformation from the hypervisors 227 on different clients 220.

The VM archiving module 250 may monitor the usage of the virtualmachines 225 executing on one or more client computers 220. The VMarchiving module 250 can obtain the usage data or information from thehypervisor 227 on each client 220. In some embodiments, the VM archivingmodule 250 communicates with the virtual center that manages andcollects information from the hypervisors 227 in order to obtain theusage information. The usage information may include storage usage(e.g., disk usage), CPU usage, memory usage, network usage, etc. Theusage information may also include various events. Such events mayinclude a set of events defined by a virtual machine software orapplication.

In some embodiments, monitoring the usage of the virtual machines 225may be implemented as storage policies. For example, one or more storagepolicies can be defined for determining what constitutes low usage forVMs 225. The same storage policy(ies) may apply to all of the VMs 225,or to a subset of the VMs 225. For instance, VMs 225 may be associatedwith particular categories, and the same storage policy(ies) may beapplied to a subset of VMs 225 associated with the same category. Suchcategories may provide information about usage pattern, characteristics,and/or level of VMs 225 belonging to the categories. A storage policymay also be defined for an individual VM 225. A separate storage policyfor each VM 225 can specify what constitutes low usage for thatparticular VM 225. For example, the storage policy can define athreshold value at which the VM 225 should be archived. The storagepolicy may be defined based on a variety of factors, such as category ofVM 225, period of peak usage, workloads handled by the VM 225, etc.

The VM archiving module 250 may monitor the usage of the virtualmachines 225 according to a schedule. For example, the VM archivingmodule 250 may repeatedly check the usage of the VMs 225 after thepassage of a pre-determined amount of time, such as on a regular basis(e.g., after a particular time interval, such as a certain number ofhours or days), or on an intermittent basis. The monitoring may also beevent-based and may be triggered by certain events. For example, usageinformation may be obtained as a part of a backup operation, and the VMarchiving module 250 may collect usage data as a scheduled (e.g., daily,weekly, etc.) backup is occurring or after a scheduled backup hascompleted. As explained above, the monitoring of VMs 225 may beimplemented as storage policies. Such policies may be run according to aschedule, on an event basis, etc. as explained above. The storagemanager 210 may manage and store storage policies.

The VM archiving module 250 can determine whether a particular VM 225 islow usage based on the obtained usage information. The VM archivingmodule 250 can determine the usage of the VM 225 based on a variety offactors, including, but not limited to: storage usage (e.g., diskusage), CPU usage, memory usage, network usage, events, etc. Forexample, the usage may be determined based on a percentage of usage forthe resources allocated to a particular VM 225. Even if a VM 225 is notbeing used, the VM 225 may have some level of activity (e.g., Windowsservices updating, virus scan running, etc.). Therefore, the VMarchiving module 250 may determine whether the activity level of a VM225 is above or at a certain level, in order to decide whether toarchive the VM 225. In some embodiments, the VM archiving module 250determines whether the usage of a VM 225 is equal to or above athreshold value. If the usage of the VM 225 is equal to or above thethreshold value, the VM archiving module 250 determines that the VM 225is not low usage. On the other hand, if the usage of the VM 225 is belowthe threshold value, the VM archiving module 250 determines that the VM225 is low usage. A VM 225 that is determined to have low utilizationmay be archived, as explained with respect to data flow step 2. In someembodiments, instead of archiving the low usage VM 225, the resourcesallocated for the VM 225 may be reduced, as explained with respect todata flow step 2 a.

At data flow step 2, the virtual machine archiving module 250 archivesthe virtual machines 225 that are determined to have low usage. Inarchiving, the source of the data may be pruned from primary storageafter the data is copied to secondary storage. If the VM archivingmodule 250 is on a different computing device from the storage manager210, the VM archiving module 250 may send a request to the storagemanager 250 to archive the VM 225. The storage manager 210 can instructone or more media agents 270 to archive the VM 225. The data associatedwith the VM 225 (e.g., residing in the information store 230 for thecorresponding client 220) may be archived along with the VM 225. Themedia agents 270 can copy the VM 225 and the associated data to one ormore secondary storage devices 280.

The virtual machines 225 may be copied to secondary storage, forexample, during a scheduled backup. If a VM 225 has not been in usesince the last backup, and a previous backup copy of the VM 225 and itsdata exists in the storage devices 280, the VM archiving module 250 maydecide not to copy the VM 225 and the data again. After the VM and itsassociated data are copied to the storage devices 280, the VM archivingmodule 250 can delete or prune the VM 225 and the associated data fromthe client 220 and the information store 230. For instance, the VMarchiving module 250 can delete a VM 225 through a command provided bythe virtual machine application. Since the source data is pruned inarchiving, the VM archiving module 250 can make sure that a backup copyof the VM 225 exists in secondary storage before removing the VM 225 andits data from primary storage. By deleting the VM 225 itself and the VMdata, the system 200 can free up unutilized and/or underutilizedresources in the primary storage and make them available for other uses.

At data flow step 2 a, the virtual machine archiving module 250 reducesthe resource allocation for virtual machines 225 that are determined tohave low usage. As explained above, in some embodiments, the VMarchiving module 250 reduces the resource allocation for the low usageVM 225, instead of archiving the VM 225. Each VM 225 may be allocated acertain amount of one or more of the following resources: storage space(e.g., disk space), CPU, memory, network resources, etc. The networkresources may refer to network bandwidth, throughput, etc. The VMarchiving module 250 may reduce the amount of resources currentlyallocated to the VM 225. For example, the VM archiving module 250 canreduce the CPU time for the VM 225 and/or reduce the storage spaceallocated to the VM 225. The VM archiving module 250 may also reduce theamount of resources by moving or migrating the VM 225 from high coststorage to low cost storage. For instance, the VM 225 and/or itsassociated data are stored on solid state drive (SSD), and if the VM 225has low utilization, the VM 225 and/or its associated data are migratedto hard disk drive. The VM archiving module 250 can also move the VM 225from fast storage to slower storage. In this manner, the cost of storagefor virtual machines 225 can be decreased by reducing the amount ofresources allocated to low usage VMs 225 and/or by migrating the lowusage VMs 225 from high cost storage to low cost storage (or faststorage to slow storage).

The VM archiving module 250 may decide to reduce the amount of resourcesallocated to a low usage VM 225, instead of archiving the VM 225, untila certain level of low usage is reached. For example, the VM archivingmodule 250 can determine a threshold value for archiving VMs 225, and ifthe usage of a VM 225 does not fall below the threshold value, the VMarchiving module 250 reduces the amount of resources allocated to theVMs 225. The VM archiving module 250 can reduce the resource allocationfor the VMs 225 in various ways. For example, the VM archiving module250 may determine the amount of resources to reduce based on the levelof usage. For example, if storage usage is greater than 25 percent andless than or equal to 30 percent, the VM archiving module 250 reducesthe storage space by half. If storage usage is greater than 20 percentand less than or equal to 25 percent, the VM archiving module 250reduces the storage space by 75 percent. The amount of resources mayalso be reduced in increments based on the level of usage. For example,if CPU usage is greater than 15 percent and less than or equal to 20percent, the VM archiving module 250 reduces the CPU time by 30%. If CPUusage is greater than 10 percent and less than or equal to 15 percent,the VMA 250 reduces the CPU time by another 30%. The amount of resourcesto be reduced can include any combination of different types ofresources that can be allocated to a VM 225.

At data flow step 3, the virtual machine archiving module 250 creates avirtual machine placeholder for each archived virtual machine 225. A VMplaceholder may be a minimal version of the VM 225 that acts as if it isthe VM 225. The VM placeholder may have a reduced set or amount ofresources compared to the VM 225. For example, the VM placeholder mayhave a minimum amount of CPU and memory allocated for it to run. The VMplaceholder may replace the VM 225 and appear to be the VM 225. The VMplaceholder can interact with one or more operating systems on the oneor more client computers 220 like it is the VM 225. To the operatingsystems, the archived VM 225 may appear to be active. For instance, theoperating systems can display the VM 225 in the list of available VMs225, and when a user selects the VM 225, the VM placeholder can act likeit is the VM 225. When a user accesses the VM placeholder, at least aportion of the VM 225 and its associated data may be restored toreactivate the VM 225. The VM placeholder may include information aboutrestoring the archived VM 225. For example, the information may includea reference to the archived VM 225, such as the location of the archivedVM 225 and its associated data in secondary storage.

In this way, a VM 225 may be archived, but still appear to be active andselectable by the user through the use of VM placeholders. Infrequentlyused VMs 225 can be moved to low cost storage without appearing to beunavailable and can be restored in a seamless manner. A VM placeholdercan be allocated a very limited amount of resources (e.g., memory anddisk space). Accordingly, the system 200 can reduce the amount of idleresources that are allocated to VMs 225, but rarely utilized.

FIG. 3 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary storage system 300 configured torestore archived virtual machines according to certain embodiments. Asillustrated, the exemplary data storage system 300 includes a storagemanager 310, a client 320, an information store 330, a virtual machine(VM) archiving module 350, one or more media agents 370, and one or moresecondary storage devices 380. A client 320 may include a hypervisor 327and one or more virtual machines (VMs) 325. The system 300 andcorresponding components of FIG. 3 may be similar to or the same as thesystem 100, 200 and similarly named components of FIGS. 1D and 2.Moreover, depending on the embodiment, the system 300 of FIG. 3 mayadditionally include any of the other components shown in FIGS. 1D and 2that are not specifically shown in FIG. 3 (e.g., one or more dataagents, one or more applications, etc.). The system 300 may include oneor more of each component. All components of the system 300 can be indirect communication with each other or communicate indirectly via theclient 320, the storage manager 310, the media agent 370, or the like.In certain embodiments, some of the components in FIG. 3 shown asseparate components can reside on a single computing device, or viceversa. For example, the virtual machine archiving module 350 can be onthe storage manager 310 or on a separate computing device.

With further reference to FIG. 3, the interaction between the variouscomponents of the exemplary data storage system will now be described ingreater detail with respect to data flow steps indicated by the numberedarrows.

At data flow step 1, a user accesses an archived virtual machine 325 ora virtual machine placeholder, e.g., at a client computer 320. The VM325 that has been archived may appear to be active. For instance, theuser may see the VM 325 in a list of available VMs 325 and select theVM. When the user selects the VM, the user may be selecting the VMplaceholder.

As explained above, a VM placeholder may be a minimal version of the VM325 that replaces the archived VM 325. The VM placeholder may have areduced set or amount of resources compared to the VM 325. For example,the VM placeholder may have a minimum amount of CPU and memory allocatedfor it to run. The VM placeholder may include information aboutrestoring the archived VM 325. Such information may include a referenceto the archived VM 325 (e.g., the location of the archived VM 325 andits associated data in secondary storage).

In some embodiments, the VM placeholder may act like it is the VM 325.The VM placeholder may interact with operating systems and/orapplications on the one or more client computers 320 as if it is theactual VM 325. For example, the VM placeholder can interact with avirtualization software (e.g., VMware, etc.) in a similar manner as theVM 325. The VM placeholder may respond to commands from thevirtualization software and communicate with the virtualization software(e.g., for notification, reporting, etc.). In one example, thevirtualization software may request a VM 325 to power on. If the VM 325has been archived, the VM placeholder can power on, report to thevirtualization software that the VM 325 is powered on, and retrieve thearchived VM 325 from secondary storage.

If a user attempts to access the VM 325 or the VM placeholder, at leasta portion of the VM 325 and/or the associated data may be restored fromsecondary storage to primary storage. From the user interfaceperspective, there may be no differences between interacting with a VM325 in primary storage and interacting with a VM placeholder for anarchived VM 325.

At data flow step 2, the client 320 sends a request to restore thearchived virtual machine 325 that has been accessed by the user to theVM archiving module 350. If the VM archiving module 350 is on adifferent computing device from the storage manager 310, the VMarchiving module 350 may send the restore request to the storage manager310. As explained above, the VM placeholder can include information forrestoring the VM 325, such as a reference to the archived VM 325. In oneembodiment, the reference is the address of the secondary storagelocation where the archived VM 325 and its associated data are stored.The VM archiving module 350 can restore the VM 325 using the reference.In this manner, the VM archiving module 350 may be able to quicklyaccess and restore the archived VM 325 from secondary storage. In someembodiments, the storage manager 310 can determine which storage devices380 have the backup copy of the VM 350 and its associated data.

At data flow step 3, the storage manager 310 instructs one or more mediaagents 370 to restore the archived virtual machine 325. The storagemanager 310 can determine which media agent(s) 370 to instruct based onthe storage devices 380 that store the backup copy of the VM 325 and theVM data. The entire backup copy of the VM 325 and the VM data may berestored to the primary storage (e.g., to the client 320 and/or theinformation store 330). In some embodiments, only a portion of the VM325 and the VM data are restored.

The VM archiving module 350 may allocate resources for the restored VM325. For example, the VM archiving module 350 may allocate a certainamount of one or more the following resources: storage space (e.g., diskspace), CPU, memory, network resources, etc. The network resources mayrefer to network bandwidth, throughput, etc. The VM placeholder mayalready have a minimum set of resources allocated to it. In suchembodiments, the VM archiving module 350 may assign the resourcesallocated to the VM placeholder to the restored VM 325. When assigningthe VM placeholder resources to the restored VM 325, the VM archivingmodule 350 may also increase the amount of resources currently allocatedto the VM placeholder and/or allocate new types resources, asappropriate.

After the archived VM 325 is restored, the VM placeholder can bedeleted. In some cases, the system 300 may not delete the VMplaceholder. For instance, if only a portion of the archived VM 325 andits data is restored, the system 300 may want to keep the VM placeholderin order to restore the remaining data. In such cases, the VMplaceholder may continue to interact with the operating systems and/orthe applications, at least partially, on behalf of the VM 325.

In addition, the system 300 may not remove the VM placeholder so that itdoes not have to create the placeholder again the next time the VM 325is archived. Archived VMs 325 are generally those with low usage, and itmay be likely that such VMs 325 are archived again at some time in thefuture after being restored. The VM placeholder can remain, and thesystem 300 may update any information as appropriate the next time theVM 325 is archived (e.g., update the information for restoring the VM325).

Because a VM 325 can remain available to the user when it is archivedand while it is being restored (e.g., through the VM placeholder), therestore of the VM 325 may appear to be “seamless” to the user. Forexample, the user may not be aware that the VM selected by the user isin secondary storage and is being restored from secondary storage. Suchuser experience may be possible because the VM 325 can be restoredquickly. “Seamless virtual machine recall” may refer to the continuousavailability of archived VMs 325 while they are in secondary storage andwhile they are being restored.

FIG. 4 is a flow diagram illustrative of one embodiment of a routine 400implemented by a data storage system for archiving virtual machines. Theroutine 400 is described with respect to the system 200 of FIG. 2.However, one or more of the steps of routine 400 may be implemented byother data storage systems, such as those described in greater detailabove with reference to FIG. 1D. The routine 400 can be implemented byany one, or a combination of, a client, a storage manager, a data agent,a virtual machine archiving module, a media agent, and the like.Moreover, further details regarding certain aspects of at least some ofsteps of the routine 400 are described in greater detail above withreference to FIG. 2. Although described in relation to backup operationsfor the purposes of illustration, the process of FIG. 4 can becompatible with other types of storage operations, such as, for example,migration, snapshots, replication operations, and the like.

At block 401, the virtual machine archiving module 250 receives ordetermines virtual machine utilization information. For example, the VMarchiving module 250 may monitor the usage of VMs 225 in the system 200.The VM archiving module 250 may monitor the VMs 225, for example,according to a schedule, based on certain events, at a systemadministrator's request, etc. The VM archiving module 250 may alsoobtain the usage information from a virtual center that collectsinformation relating to various VMs 225 in the system 200.

At block 402, if the utilization of a virtual machine 225 is low, the VMarchiving module 250 sends instructions to archive the virtual machine225 at block 403. The determination of utilization level may be based ona number of factors (e.g., usage level of various types of resourcesassociated with the VM 225). If the VM archiving module 250 is not onthe storage manager 210, the VM archiving module 250 may forward theinstructions to the storage manager 210. The storage manager 210 caninstruct the media agents 270 to archive the VM 225. After the backup ofthe VM 225 and/or the associated data is complete, the VM 225 and thedata are deleted from primary storage.

At block 404, the VM archiving module 250 creates a VM placeholder forthe archived VM 225. The VM placeholder may appear to be the VM 225 andcan interact with the operating systems on the clients 220 in a waysimilar to the VM 225. In this manner, the VM 225 can appear to beavailable and selectable by the user after it has been archived.

The routine 400 can include fewer, more, or different blocks than thoseillustrated in FIG. 4 without departing from the spirit and scope of thedescription. Moreover, it will be appreciated by those skilled in theart and others that some or all of the functions described in thisdisclosure may be embodied in software executed by one or moreprocessors of the disclosed components and mobile communication devices.The software may be persistently stored in any type of non-volatilestorage.

FIG. 5 is a flow diagram illustrative of one embodiment of a routine 500implemented by a data storage system for restoring archived virtualmachines. The routine 500 is described with respect to the system 300 ofFIG. 3. However, one or more of the steps of routine 500 may beimplemented by other data storage systems, such as those described ingreater detail above with reference to FIGS. 1D and 2. The routine 500can be implemented by any one, or a combination of, a client, a storagemanager, a data agent, a virtual machine archiving module, a mediaagent, and the like. Moreover, further details regarding certain aspectsof at least some of steps of the routine 500 are described in greaterdetail above with reference to FIG. 3. Although described in relation tobackup operations for the purposes of illustration, the process of FIG.5 can be compatible with other types of storage operations, such as, forexample, migration, snapshots, replication operations, and the like.

At block 501, the virtual machine archiving module 350 receives arequest to restore a virtual machine 325. Such request may be receivedwhen a user accesses an archived VM 325 or a VM placeholder, e.g., at aclient 320. The request may be for the entire VM 325 and its associateddata, or may be for only a portion of the VM 325 and the VM data.

At block 502, the VM archiving module 350 sends instructions to restorethe virtual machine 325. If the VM archiving module 350 is not on thestorage manager 310, the VM archiving module 350 may forward theinstructions to the storage manager 310. The storage manager 310 caninstruct one or more media agents 380 to restore the requested VM 325.The media agents 380 can retrieve the backup copy of the VM 325 and theVM data from the corresponding secondary storage devices 380.

At block 503, the VM archiving module 350 replaces the VM placeholderwith the restored VM 325. If all of the VM 350 and the associated dataare restored, the VM archiving module 350 may replace the VM placeholderwith the restored VM 325. The VM placeholder can then be removed fromprimary storage.

At block 504, the client 320 executes the restored VM 325. In general, aVM 325 can appear to be available to a user, regardless of whether theVM 325 is archived or not. However, once the VM 325 is restored toprimary storage, the user can have access to the actual VM 325.

The routine 500 can include fewer, more, or different blocks than thoseillustrated in FIG. 5 without departing from the spirit and scope of thedescription. Moreover, it will be appreciated by those skilled in theart and others that some or all of the functions described in thisdisclosure may be embodied in software executed by one or moreprocessors of the disclosed components and mobile communication devices.The software may be persistently stored in any type of non-volatilestorage.

Terminology

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Depending on the embodiment, certain acts, events, or functions of anyof the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out all together (e.g., not alldescribed acts or events are necessary for the practice of thealgorithms). Moreover, in certain embodiments, acts or events can beperformed concurrently, e.g., through multi-threaded processing,interrupt processing, or multiple processors or processor cores or onother parallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described herein. Software and other modulesmay reside on servers, workstations, personal computers, computerizedtablets, PDAs, and other devices suitable for the purposes describedherein. Software and other modules may be accessible via local memory,via a network, via a browser, or via other means suitable for thepurposes described herein. Data structures described herein may comprisecomputer files, variables, programming arrays, programming structures,or any electronic information storage schemes or methods, or anycombinations thereof, suitable for the purposes described herein. Userinterface elements described herein may comprise elements from graphicaluser interfaces, command line interfaces, and other suitable interfaces.

Further, the processing of the various components of the illustratedsystems can be distributed across multiple machines, networks, and othercomputing resources. In addition, two or more components of a system canbe combined into fewer components. Various components of the illustratedsystems can be implemented in one or more virtual machines, rather thanin dedicated computer hardware systems. Likewise, the data repositoriesshown can represent physical and/or logical data storage, including, forexample, storage area networks or other distributed storage systems.Moreover, in some embodiments the connections between the componentsshown represent possible paths of data flow, rather than actualconnections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the acts specified in the flow chart and/or block diagramblock or blocks.

These computer program instructions may also be stored in acomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operations to be performed on the computer or otherprogrammable apparatus to produce a computer implemented process suchthat the instructions which execute on the computer or otherprogrammable apparatus provide steps for implementing the acts specifiedin the flow chart and/or block diagram block or blocks.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel methods and systems describedherein may be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the describedmethods and systems may be made without departing from the spirit of thedisclosure. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the disclosure.

What is claimed is:
 1. A method of creating virtual machine placeholdersin a networked data storage system comprising: receiving usage dataabout one or more virtual machines existing on one or more primarystorage devices, the one or more primary storage devices comprisingcomputer hardware; creating a virtual machine placeholder for a firstvirtual machine of the one or more virtual machines existing on the oneor more primary storage devices based at least in part on usage of thefirst virtual machine, the virtual machine placeholder is created atleast in part during one or more backups that copy data associated withthe first virtual machine from the one or more primary storage devicesto one or more secondary storage devices, the virtual machineplaceholder is recognized as the first virtual machine by one or morevirtualization applications, and wherein the virtual machine placeholdercomprises information usable in restoring the first virtual machine fromthe one or more secondary storage devices to the one or more primarystorage devices; replacing the first virtual machine with the firstvirtual machine placeholder in the one or more primary storage devices;and deleting at least a portion of the data associated with the firstvirtual machine from the one or more primary storage devices during theone or more backups.
 2. The method of claim 1 wherein the first virtualmachine is selectable by a user using the virtual machine placeholder.3. The method of claim 1 wherein the virtual machine placeholderinteracts with one or more virtualization applications as if the virtualmachine placeholder were the first virtual machine.
 4. The method ofclaim 1 wherein the virtual machine placeholder comprises a reference tothe copy data associated with the first virtual machine in the secondarystorage subsystem.
 5. The method of claim 4 wherein the reference is anaddress of a location in the secondary storage subsystem where the copydata associated with the first virtual machine is stored.
 6. The methodof claim 1 wherein the virtual machine placeholder comprises a reducedamount of resources in comparison to the first virtual machine.
 7. Themethod of claim 1 wherein the virtual machine placeholder is createdwhen the usage of the first virtual machine is less than a thresholddefined in a storage policy.
 8. The method of claim 1 wherein thevirtual machine placeholder is a reduced version of the first virtualmachine.
 9. The method of claim 1 wherein monitoring the usage of theone or more virtual machines occurs at least in part during the one ormore backups.
 10. The method of claim 1 wherein the virtual machineplaceholder interacts with an operating system or the one or morevirtualization applications as if the first virtual machine had not beendeleted.
 11. A data storage system that creates virtual machineplaceholders comprising: a storage manager executing on computerhardware comprising one or more computing devices, the storage managerreceives usage data about of one or more virtual machines existing onone or more primary storage devices comprising computer hardware; thestorage manager directs creation of a virtual machine placeholder for afirst virtual machine of the one or more virtual machines existing onthe one or more primary storage devices at least in part on usage of thefirst virtual machine; the virtual machine placeholder is created atleast in part during one or more backups that copy data associated withthe first virtual machine from the one or more primary storage devicesto one or more secondary storage devices, the virtual machineplaceholder is recognized as the first virtual machine by one or morevirtualization applications, and the virtual machine placeholdercomprises information usable in restoring the first virtual machine fromthe one or more secondary storage devices to the one or more primarystorage devices; the storage manager directs replacement of the firstvirtual machine with the first virtual machine placeholder in the one ormore primary storage devices; and the storage manager directs deletionof at least a portion of the data associated with the first virtualmachine from the one or more primary storage devices during the one ormore backups.
 12. The data storage system of claim 11 wherein the firstvirtual machine is selectable by a user using the virtual machineplaceholder.
 13. The data storage system of claim 11 wherein the virtualmachine placeholder interacts with an operating system or the one ormore virtualization applications as if it were the first virtualmachine.
 14. The data storage system of claim 11 wherein the virtualmachine placeholder comprises a reference to t the copy data associatedwith the first virtual machine in the secondary storage subsystem. 15.The data storage system of claim 14 wherein the reference is an addressof a location in the secondary storage subsystem where the copy dataassociated with the first virtual machine is stored.
 16. The datastorage system of claim 11 wherein the virtual machine placeholdercomprises a reduced amount of resources in comparison to the firstvirtual machine.
 17. The data storage system of claim 11 wherein thevirtual machine placeholder is created when the usage of the firstvirtual machine is less than a threshold defined in a storage policy.18. The data storage system of claim 11 wherein the virtual machineplaceholder is a reduced version of the first virtual machine.
 19. Thedata storage system of claim 11 wherein monitoring the usage of the oneor more virtual machines occurs at least in part during the one or morebackups.
 20. The data storage system of claim 11 wherein the virtualmachine placeholder interacts with an operating system or the one ormore virtualization applications as if the first virtual machine had notbeen deleted.